style(3p/nix): Final act in the brace-wrapping saga r/777

This last change set was generated by a full clang-tidy run (including
compilation):

    clang-tidy -p ~/projects/nix-build/ \
      -checks=-*,readability-braces-around-statements -fix src/*/*.cc

Actually running clang-tidy requires some massaging to make it play
nice with Nix + meson, I'll be adding a wrapper or something for that soon.

84 files changed, 2603 insertions, 1556 deletions

diff --git a/third_party/default.nix b/third_party/default.nix
index 16d99cadf3..b48f405eba 100644
--- a/third_party/default.nix
+++ b/third_party/default.nix
@@ -33,6 +33,7 @@ let
       cairo
       cargo
       cgit
+      clang-tools
       clangStdenv
       clang_9
       cmake
diff --git a/third_party/nix/default.nix b/third_party/nix/default.nix
index a62f16b4a2..263878cea4 100644
--- a/third_party/nix/default.nix
+++ b/third_party/nix/default.nix
@@ -20,6 +20,7 @@ in stdenv.mkDerivation {
 
   nativeBuildInputs = with pkgs; [
     bison
+    clang-tools
     meson
     ninja
     pkgconfig
diff --git a/third_party/nix/src/build-remote/build-remote.cc b/third_party/nix/src/build-remote/build-remote.cc
index dd7aea9679..ef139c6bdc 100644
--- a/third_party/nix/src/build-remote/build-remote.cc
+++ b/third_party/nix/src/build-remote/build-remote.cc
@@ -39,10 +39,11 @@ static AutoCloseFD openSlotLock(const Machine& m, unsigned long long slot) {
 }
 
 static bool allSupportedLocally(const std::set<std::string>& requiredFeatures) {
-  for (auto& feature : requiredFeatures)
+  for (auto& feature : requiredFeatures) {
     if (!settings.systemFeatures.get().count(feature)) {
       return false;
     }
+  }
   return true;
 }
 
@@ -172,10 +173,11 @@ static int _main(int argc, char** argv) {
         }
 
         if (!bestSlotLock) {
-          if (rightType && !canBuildLocally)
+          if (rightType && !canBuildLocally) {
             std::cerr << "# postpone\n";
-          else
+          } else {
             std::cerr << "# decline\n";
+          }
           break;
         }
 
@@ -194,8 +196,9 @@ static int _main(int argc, char** argv) {
           if (hasPrefix(bestMachine->storeUri, "ssh://")) {
             storeParams["max-connections"] = "1";
             storeParams["log-fd"] = "4";
-            if (bestMachine->sshKey != "")
+            if (bestMachine->sshKey != "") {
               storeParams["ssh-key"] = bestMachine->sshKey;
+            }
           }
 
           sshStore = openStore(bestMachine->storeUri, storeParams);
@@ -254,15 +257,17 @@ static int _main(int argc, char** argv) {
 
     auto result = sshStore->buildDerivation(drvPath, drv);
 
-    if (!result.success())
+    if (!result.success()) {
       throw Error("build of '%s' on '%s' failed: %s", drvPath, storeUri,
                   result.errorMsg);
+    }
 
     PathSet missing;
-    for (auto& path : outputs)
+    for (auto& path : outputs) {
       if (!store->isValidPath(path)) {
         missing.insert(path);
       }
+    }
 
     if (!missing.empty()) {
       DLOG(INFO) << "copying outputs from '" << storeUri << "'";
diff --git a/third_party/nix/src/libexpr/attr-path.cc b/third_party/nix/src/libexpr/attr-path.cc
index edab0b6df9..3d4e9c1e10 100644
--- a/third_party/nix/src/libexpr/attr-path.cc
+++ b/third_party/nix/src/libexpr/attr-path.cc
@@ -16,16 +16,18 @@ static Strings parseAttrPath(const string& s) {
     } else if (*i == '"') {
       ++i;
       while (1) {
-        if (i == s.end())
+        if (i == s.end()) {
           throw Error(format("missing closing quote in selection path '%1%'") %
                       s);
+        }
         if (*i == '"') {
           break;
         }
         cur.push_back(*i++);
       }
-    } else
+    } else {
       cur.push_back(*i);
+    }
     ++i;
   }
   if (!cur.empty()) {
@@ -62,33 +64,38 @@ Value* findAlongAttrPath(EvalState& state, const string& attrPath,
        according to what is specified in the attrPath. */
 
     if (apType == apAttr) {
-      if (v->type != tAttrs)
+      if (v->type != tAttrs) {
         throw TypeError(format("the expression selected by the selection path "
                                "'%1%' should be a set but is %2%") %
                         attrPath % showType(*v));
+      }
 
-      if (attr.empty())
+      if (attr.empty()) {
         throw Error(format("empty attribute name in selection path '%1%'") %
                     attrPath);
+      }
 
       Bindings::iterator a = v->attrs->find(state.symbols.create(attr));
-      if (a == v->attrs->end())
+      if (a == v->attrs->end()) {
         throw Error(
             format("attribute '%1%' in selection path '%2%' not found") % attr %
             attrPath);
+      }
       v = &*a->value;
     }
 
     else if (apType == apIndex) {
-      if (!v->isList())
+      if (!v->isList()) {
         throw TypeError(format("the expression selected by the selection path "
                                "'%1%' should be a list but is %2%") %
                         attrPath % showType(*v));
+      }
 
-      if (attrIndex >= v->listSize())
+      if (attrIndex >= v->listSize()) {
         throw Error(
             format("list index %1% in selection path '%2%' is out of range") %
             attrIndex % attrPath);
+      }
 
       v = v->listElems()[attrIndex];
     }
diff --git a/third_party/nix/src/libexpr/attr-set.cc b/third_party/nix/src/libexpr/attr-set.cc
index d5bedbae43..fe1bf080ed 100644
--- a/third_party/nix/src/libexpr/attr-set.cc
+++ b/third_party/nix/src/libexpr/attr-set.cc
@@ -10,8 +10,9 @@ namespace nix {
    capacity. The space is implicitly reserved after the Bindings
    structure. */
 Bindings* EvalState::allocBindings(size_t capacity) {
-  if (capacity > std::numeric_limits<Bindings::size_t>::max())
+  if (capacity > std::numeric_limits<Bindings::size_t>::max()) {
     throw Error("attribute set of size %d is too big", capacity);
+  }
   return new (allocBytes(sizeof(Bindings) + sizeof(Attr) * capacity))
       Bindings((Bindings::size_t)capacity);
 }
diff --git a/third_party/nix/src/libexpr/common-eval-args.cc b/third_party/nix/src/libexpr/common-eval-args.cc
index 8cd4bc56e5..7af4d6b276 100644
--- a/third_party/nix/src/libexpr/common-eval-args.cc
+++ b/third_party/nix/src/libexpr/common-eval-args.cc
@@ -36,11 +36,12 @@ Bindings* MixEvalArgs::getAutoArgs(EvalState& state) {
   Bindings* res = state.allocBindings(autoArgs.size());
   for (auto& i : autoArgs) {
     Value* v = state.allocValue();
-    if (i.second[0] == 'E')
+    if (i.second[0] == 'E') {
       state.mkThunk_(
           *v, state.parseExprFromString(string(i.second, 1), absPath(".")));
-    else
+    } else {
       mkString(*v, string(i.second, 1));
+    }
     res->push_back(Attr(state.symbols.create(i.first), v));
   }
   res->sort();
@@ -55,8 +56,9 @@ Path lookupFileArg(EvalState& state, string s) {
   } else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
     Path p = s.substr(1, s.size() - 2);
     return state.findFile(p);
-  } else
+  } else {
     return absPath(s);
+  }
 }
 
 }  // namespace nix
diff --git a/third_party/nix/src/libexpr/eval.cc b/third_party/nix/src/libexpr/eval.cc
index 0ceb4d750b..c5329daf5f 100644
--- a/third_party/nix/src/libexpr/eval.cc
+++ b/third_party/nix/src/libexpr/eval.cc
@@ -62,17 +62,19 @@ static void printValue(std::ostream& str, std::set<const Value*>& active,
       break;
     case tString:
       str << "\"";
-      for (const char* i = v.string.s; *i; i++)
-        if (*i == '\"' || *i == '\\')
+      for (const char* i = v.string.s; *i; i++) {
+        if (*i == '\"' || *i == '\\') {
           str << "\\" << *i;
-        else if (*i == '\n')
+        } else if (*i == '\n') {
           str << "\\n";
-        else if (*i == '\r')
+        } else if (*i == '\r') {
           str << "\\r";
-        else if (*i == '\t')
+        } else if (*i == '\t') {
           str << "\\t";
-        else
+        } else {
           str << *i;
+        }
+      }
       str << "\"";
       break;
     case tPath:
@@ -281,7 +283,9 @@ static Strings parseNixPath(const string& s) {
     if (*p == ':') {
       if (isUri(std::string(start2, s.end()))) {
         ++p;
-        while (p != s.end() && *p != ':') ++p;
+        while (p != s.end() && *p != ':') {
+          ++p;
+        }
       }
       res.push_back(std::string(start, p));
       if (p == s.end()) {
@@ -361,8 +365,9 @@ EvalState::EvalState(const Strings& _searchPath, ref<Store> store)
         for (auto& path : closure) {
           allowedPaths->insert(path);
         }
-      } else
+      } else {
         allowedPaths->insert(r.second);
+      }
     }
   }
 
@@ -400,9 +405,10 @@ Path EvalState::checkSourcePath(const Path& path_) {
     }
   }
 
-  if (!found)
+  if (!found) {
     throw RestrictedPathError(
         "access to path '%1%' is forbidden in restricted mode", abspath);
+  }
 
   /* Resolve symlinks. */
   DLOG(INFO) << "checking access to '" << abspath << "'";
@@ -428,12 +434,14 @@ void EvalState::checkURI(const std::string& uri) {
      prefix. Thus, the prefix https://github.co does not permit
      access to https://github.com. Note: this allows 'http://' and
      'https://' as prefixes for any http/https URI. */
-  for (auto& prefix : evalSettings.allowedUris.get())
+  for (auto& prefix : evalSettings.allowedUris.get()) {
     if (uri == prefix ||
         (uri.size() > prefix.size() && prefix.size() > 0 &&
          hasPrefix(uri, prefix) &&
-         (prefix[prefix.size() - 1] == '/' || uri[prefix.size()] == '/')))
+         (prefix[prefix.size() - 1] == '/' || uri[prefix.size()] == '/'))) {
       return;
+    }
+  }
 
   /* If the URI is a path, then check it against allowedPaths as
      well. */
@@ -600,9 +608,10 @@ inline Value* EvalState::lookupVar(Env* env, const ExprVar& var, bool noEval) {
       }
       return j->value;
     }
-    if (!env->prevWith)
+    if (!env->prevWith) {
       throwUndefinedVarError("undefined variable '%1%' at %2%", var.name,
                              var.pos);
+    }
     for (size_t l = env->prevWith; l; --l, env = env->up) {
       ;
     }
@@ -622,8 +631,9 @@ Value* EvalState::allocValue() {
 }
 
 Env& EvalState::allocEnv(size_t size) {
-  if (size > std::numeric_limits<decltype(Env::size)>::max())
+  if (size > std::numeric_limits<decltype(Env::size)>::max()) {
     throw Error("environment size %d is too big", size);
+  }
 
   nrEnvs++;
   nrValuesInEnvs += size;
@@ -669,8 +679,9 @@ void EvalState::mkPos(Value& v, Pos* pos) {
     mkInt(*allocAttr(v, sLine), pos->line);
     mkInt(*allocAttr(v, sColumn), pos->column);
     v.attrs->sort();
-  } else
+  } else {
     mkNull(v);
+  }
 }
 
 /* Create a thunk for the delayed computation of the given expression
@@ -823,8 +834,9 @@ void ExprAttrs::eval(EvalState& state, Env& env, Value& v) {
       if (hasOverrides && !i.second.inherited) {
         vAttr = state.allocValue();
         mkThunk(*vAttr, env2, i.second.e);
-      } else
+      } else {
         vAttr = i.second.e->maybeThunk(state, i.second.inherited ? env : env2);
+      }
       env2.values[displ++] = vAttr;
       v.attrs->push_back(Attr(i.first, vAttr, &i.second.pos));
     }
@@ -850,16 +862,18 @@ void ExprAttrs::eval(EvalState& state, Env& env, Value& v) {
         if (j != attrs.end()) {
           (*newBnds)[j->second.displ] = i;
           env2.values[j->second.displ] = i.value;
-        } else
+        } else {
           newBnds->push_back(i);
+        }
       }
       newBnds->sort();
       v.attrs = newBnds;
     }
   } else {
-    for (auto& i : attrs)
+    for (auto& i : attrs) {
       v.attrs->push_back(
           Attr(i.first, i.second.e->maybeThunk(state, env), &i.second.pos));
+    }
   }
 
   /* Dynamic attrs apply *after* rec and __overrides. */
@@ -873,9 +887,10 @@ void ExprAttrs::eval(EvalState& state, Env& env, Value& v) {
     state.forceStringNoCtx(nameVal);
     Symbol nameSym = state.symbols.create(nameVal.string.s);
     Bindings::iterator j = v.attrs->find(nameSym);
-    if (j != v.attrs->end())
+    if (j != v.attrs->end()) {
       throwEvalError("dynamic attribute '%1%' at %2% already defined at %3%",
                      nameSym, i.pos, *j->pos);
+    }
 
     i.valueExpr->setName(nameSym);
     /* Keep sorted order so find can catch duplicates */
@@ -895,17 +910,19 @@ void ExprLet::eval(EvalState& state, Env& env, Value& v) {
      while the inherited attributes are evaluated in the original
      environment. */
   size_t displ = 0;
-  for (auto& i : attrs->attrs)
+  for (auto& i : attrs->attrs) {
     env2.values[displ++] =
         i.second.e->maybeThunk(state, i.second.inherited ? env : env2);
+  }
 
   body->eval(state, env2, v);
 }
 
 void ExprList::eval(EvalState& state, Env& env, Value& v) {
   state.mkList(v, elems.size());
-  for (size_t n = 0; n < elems.size(); ++n)
+  for (size_t n = 0; n < elems.size(); ++n) {
     v.listElems()[n] = elems[n]->maybeThunk(state, env);
+  }
 }
 
 void ExprVar::eval(EvalState& state, Env& env, Value& v) {
@@ -919,10 +936,11 @@ static string showAttrPath(EvalState& state, Env& env,
   std::ostringstream out;
   bool first = true;
   for (auto& i : attrPath) {
-    if (!first)
+    if (!first) {
       out << '.';
-    else
+    } else {
       first = false;
+    }
     try {
       out << getName(i, state, env);
     } catch (Error& e) {
@@ -956,8 +974,9 @@ void ExprSelect::eval(EvalState& state, Env& env, Value& v) {
         }
       } else {
         state.forceAttrs(*vAttrs, pos);
-        if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
+        if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) {
           throwEvalError("attribute '%1%' missing, at %2%", name, pos);
+        }
       }
       vAttrs = j->value;
       pos2 = j->pos;
@@ -969,9 +988,10 @@ void ExprSelect::eval(EvalState& state, Env& env, Value& v) {
     state.forceValue(*vAttrs, (pos2 != NULL ? *pos2 : this->pos));
 
   } catch (Error& e) {
-    if (pos2 && pos2->file != state.sDerivationNix)
+    if (pos2 && pos2->file != state.sDerivationNix) {
       addErrorPrefix(e, "while evaluating the attribute '%1%' at %2%:\n",
                      showAttrPath(state, env, attrPath), *pos2);
+    }
     throw;
   }
 
@@ -1112,9 +1132,10 @@ void EvalState::callFunction(Value& fun, Value& arg, Value& v, const Pos& pos) {
     for (auto& i : lambda.formals->formals) {
       Bindings::iterator j = arg.attrs->find(i.name);
       if (j == arg.attrs->end()) {
-        if (!i.def)
+        if (!i.def) {
           throwTypeError("%1% called without required argument '%2%', at %3%",
                          lambda, i.name, pos);
+        }
         env2.values[displ++] = i.def->maybeThunk(*this, env2);
       } else {
         attrsUsed++;
@@ -1127,11 +1148,13 @@ void EvalState::callFunction(Value& fun, Value& arg, Value& v, const Pos& pos) {
     if (!lambda.formals->ellipsis && attrsUsed != arg.attrs->size()) {
       /* Nope, so show the first unexpected argument to the
          user. */
-      for (auto& i : *arg.attrs)
+      for (auto& i : *arg.attrs) {
         if (lambda.formals->argNames.find(i.name) ==
-            lambda.formals->argNames.end())
+            lambda.formals->argNames.end()) {
           throwTypeError("%1% called with unexpected argument '%2%', at %3%",
                          lambda, i.name, pos);
+        }
+      }
       abort();  // can't happen
     }
   }
@@ -1143,15 +1166,17 @@ void EvalState::callFunction(Value& fun, Value& arg, Value& v, const Pos& pos) {
 
   /* Evaluate the body.  This is conditional on showTrace, because
      catching exceptions makes this function not tail-recursive. */
-  if (settings.showTrace) try {
+  if (settings.showTrace) {
+    try {
       lambda.body->eval(*this, env2, v);
     } catch (Error& e) {
       addErrorPrefix(e, "while evaluating %1%, called from %2%:\n", lambda,
                      pos);
       throw;
     }
-  else
+  } else {
     fun.lambda.fun->body->eval(*this, env2, v);
+  }
 }
 
 // Lifted out of callFunction() because it creates a temporary that
@@ -1181,13 +1206,14 @@ void EvalState::autoCallFunction(Bindings& args, Value& fun, Value& res) {
 
   for (auto& i : fun.lambda.fun->formals->formals) {
     Bindings::iterator j = args.find(i.name);
-    if (j != args.end())
+    if (j != args.end()) {
       actualArgs->attrs->push_back(*j);
-    else if (!i.def)
+    } else if (!i.def) {
       throwTypeError(
           "cannot auto-call a function that has an argument without a default "
           "value ('%1%')",
           i.name);
+    }
   }
 
   actualArgs->attrs->sort();
@@ -1278,10 +1304,11 @@ void ExprOpUpdate::eval(EvalState& state, Env& env, Value& v) {
       v.attrs->push_back(*j);
       ++i;
       ++j;
-    } else if (i->name < j->name)
+    } else if (i->name < j->name) {
       v.attrs->push_back(*i++);
-    else
+    } else {
       v.attrs->push_back(*j++);
+    }
   }
 
   while (i != v1.attrs->end()) {
@@ -1364,20 +1391,23 @@ void ExprConcatStrings::eval(EvalState& state, Env& env, Value& v) {
         firstType = tFloat;
         nf = n;
         nf += vTmp.fpoint;
-      } else
+      } else {
         throwEvalError("cannot add %1% to an integer, at %2%", showType(vTmp),
                        pos);
+      }
     } else if (firstType == tFloat) {
       if (vTmp.type == tInt) {
         nf += vTmp.integer;
       } else if (vTmp.type == tFloat) {
         nf += vTmp.fpoint;
-      } else
+      } else {
         throwEvalError("cannot add %1% to a float, at %2%", showType(vTmp),
                        pos);
-    } else
+      }
+    } else {
       s << state.coerceToString(pos, vTmp, context, false,
                                 firstType == tString);
+    }
   }
 
   if (firstType == tInt) {
@@ -1385,11 +1415,12 @@ void ExprConcatStrings::eval(EvalState& state, Env& env, Value& v) {
   } else if (firstType == tFloat) {
     mkFloat(v, nf);
   } else if (firstType == tPath) {
-    if (!context.empty())
+    if (!context.empty()) {
       throwEvalError(
           "a string that refers to a store path cannot be appended to a path, "
           "at %1%",
           pos);
+    }
     auto path = canonPath(s.str());
     mkPath(v, path.c_str());
   } else {
@@ -1415,13 +1446,15 @@ void EvalState::forceValueDeep(Value& v) {
     forceValue(v);
 
     if (v.type == tAttrs) {
-      for (auto& i : *v.attrs) try {
+      for (auto& i : *v.attrs) {
+        try {
           recurse(*i.value);
         } catch (Error& e) {
           addErrorPrefix(e, "while evaluating the attribute '%1%' at %2%:\n",
                          i.name, *i.pos);
           throw;
         }
+      }
     } else if (v.isList()) {
       for (size_t n = 0; n < v.listSize(); ++n) {
         recurse(*v.listElems()[n]);
@@ -1486,10 +1519,11 @@ string EvalState::forceString(Value& v, const Pos& pos) {
 }
 
 void copyContext(const Value& v, PathSet& context) {
-  if (v.string.context)
+  if (v.string.context) {
     for (const char** p = v.string.context; *p; ++p) {
       context.insert(*p);
     }
+  }
 }
 
 string EvalState::forceString(Value& v, PathSet& context, const Pos& pos) {
@@ -1501,16 +1535,17 @@ string EvalState::forceString(Value& v, PathSet& context, const Pos& pos) {
 string EvalState::forceStringNoCtx(Value& v, const Pos& pos) {
   string s = forceString(v, pos);
   if (v.string.context) {
-    if (pos)
+    if (pos) {
       throwEvalError(
           "the string '%1%' is not allowed to refer to a store path (such as "
           "'%2%'), at %3%",
           v.string.s, v.string.context[0], pos);
-    else
+    } else {
       throwEvalError(
           "the string '%1%' is not allowed to refer to a store path (such as "
           "'%2%')",
           v.string.s, v.string.context[0]);
+    }
   }
   return s;
 }
@@ -1567,13 +1602,15 @@ string EvalState::coerceToString(const Pos& pos, Value& v, PathSet& context,
       return *maybeString;
     }
     auto i = v.attrs->find(sOutPath);
-    if (i == v.attrs->end())
+    if (i == v.attrs->end()) {
       throwTypeError("cannot coerce a set to a string, at %1%", pos);
+    }
     return coerceToString(pos, *i->value, context, coerceMore, copyToStore);
   }
 
-  if (v.type == tExternal)
+  if (v.type == tExternal) {
     return v.external->coerceToString(pos, context, coerceMore, copyToStore);
+  }
 
   if (coerceMore) {
     /* Note that `false' is represented as an empty string for
@@ -1601,9 +1638,10 @@ string EvalState::coerceToString(const Pos& pos, Value& v, PathSet& context,
                                  copyToStore);
         if (n < v.listSize() - 1
             /* !!! not quite correct */
-            &&
-            (!v.listElems()[n]->isList() || v.listElems()[n]->listSize() != 0))
+            && (!v.listElems()[n]->isList() ||
+                v.listElems()[n]->listSize() != 0)) {
           result += " ";
+        }
       }
       return result;
     }
@@ -1613,13 +1651,14 @@ string EvalState::coerceToString(const Pos& pos, Value& v, PathSet& context,
 }
 
 string EvalState::copyPathToStore(PathSet& context, const Path& path) {
-  if (nix::isDerivation(path))
+  if (nix::isDerivation(path)) {
     throwEvalError("file names are not allowed to end in '%1%'", drvExtension);
+  }
 
   Path dstPath;
-  if (srcToStore[path] != "")
+  if (srcToStore[path] != "") {
     dstPath = srcToStore[path];
-  else {
+  } else {
     dstPath =
         settings.readOnlyMode
             ? store
@@ -1638,9 +1677,10 @@ string EvalState::copyPathToStore(PathSet& context, const Path& path) {
 
 Path EvalState::coerceToPath(const Pos& pos, Value& v, PathSet& context) {
   string path = coerceToString(pos, v, context, false, false);
-  if (path == "" || path[0] != '/')
+  if (path == "" || path[0] != '/') {
     throwEvalError("string '%1%' doesn't represent an absolute path, at %2%",
                    path, pos);
+  }
   return path;
 }
 
@@ -1827,10 +1867,11 @@ void EvalState::printStats() {
         auto list = topObj.list("functions");
         for (auto& i : functionCalls) {
           auto obj = list.object();
-          if (i.first->name.set())
+          if (i.first->name.set()) {
             obj.attr("name", (const string&)i.first->name);
-          else
+          } else {
             obj.attr("name", nullptr);
+          }
           if (i.first->pos) {
             obj.attr("file", (const string&)i.first->pos.file);
             obj.attr("line", i.first->pos.line);
@@ -1885,10 +1926,11 @@ size_t valueSize(Value& v) {
     switch (v.type) {
       case tString:
         sz += doString(v.string.s);
-        if (v.string.context)
+        if (v.string.context) {
           for (const char** p = v.string.context; *p; ++p) {
             sz += doString(*p);
           }
+        }
         break;
       case tPath:
         sz += doString(v.path);
@@ -1908,8 +1950,9 @@ size_t valueSize(Value& v) {
         if (seen.find(v.listElems()) == seen.end()) {
           seen.insert(v.listElems());
           sz += v.listSize() * sizeof(Value*);
-          for (size_t n = 0; n < v.listSize(); ++n)
+          for (size_t n = 0; n < v.listSize(); ++n) {
             sz += doValue(*v.listElems()[n]);
+          }
         }
         break;
       case tThunk:
@@ -1947,11 +1990,13 @@ size_t valueSize(Value& v) {
 
     size_t sz = sizeof(Env) + sizeof(Value*) * env.size;
 
-    if (env.type != Env::HasWithExpr)
-      for (size_t i = 0; i < env.size; ++i)
+    if (env.type != Env::HasWithExpr) {
+      for (size_t i = 0; i < env.size; ++i) {
         if (env.values[i]) {
           sz += doValue(*env.values[i]);
         }
+      }
+    }
 
     if (env.up) {
       sz += doEnv(*env.up);
diff --git a/third_party/nix/src/libexpr/get-drvs.cc b/third_party/nix/src/libexpr/get-drvs.cc
index 8897db4be9..c62e05d454 100644
--- a/third_party/nix/src/libexpr/get-drvs.cc
+++ b/third_party/nix/src/libexpr/get-drvs.cc
@@ -25,18 +25,20 @@ DrvInfo::DrvInfo(EvalState& state, ref<Store> store,
 
   name = storePathToName(drvPath);
 
-  if (spec.second.size() > 1)
+  if (spec.second.size() > 1) {
     throw Error(
         "building more than one derivation output is not supported, in '%s'",
         drvPathWithOutputs);
+  }
 
   outputName = spec.second.empty() ? get(drv.env, "outputName", "out")
                                    : *spec.second.begin();
 
   auto i = drv.outputs.find(outputName);
-  if (i == drv.outputs.end())
+  if (i == drv.outputs.end()) {
     throw Error("derivation '%s' does not have output '%s'", drvPath,
                 outputName);
+  }
 
   outPath = i->second.path;
 }
@@ -110,8 +112,9 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool onlyOutputsToInstall) {
         outputs[name] =
             state->coerceToPath(*outPath->pos, *outPath->value, context);
       }
-    } else
+    } else {
       outputs["out"] = queryOutPath();
+    }
   }
   if (!onlyOutputsToInstall || !attrs) {
     return outputs;
@@ -363,10 +366,11 @@ static void getDerivations(EvalState& state, Value& vIn,
   state.autoCallFunction(autoArgs, vIn, v);
 
   /* Process the expression. */
-  if (!getDerivation(state, v, pathPrefix, drvs, done, ignoreAssertionFailures))
+  if (!getDerivation(state, v, pathPrefix, drvs, done,
+                     ignoreAssertionFailures)) {
     ;
 
-  else if (v.type == tAttrs) {
+  } else if (v.type == tAttrs) {
     /* !!! undocumented hackery to support combining channels in
        nix-env.cc. */
     bool combineChannels =
@@ -384,11 +388,11 @@ static void getDerivations(EvalState& state, Value& vIn,
         continue;
       }
       string pathPrefix2 = addToPath(pathPrefix, i->name);
-      if (combineChannels)
+      if (combineChannels) {
         getDerivations(state, *i->value, pathPrefix2, autoArgs, drvs, done,
                        ignoreAssertionFailures);
-      else if (getDerivation(state, *i->value, pathPrefix2, drvs, done,
-                             ignoreAssertionFailures)) {
+      } else if (getDerivation(state, *i->value, pathPrefix2, drvs, done,
+                               ignoreAssertionFailures)) {
         /* If the value of this attribute is itself a set,
            should we recurse into it?  => Only if it has a
            `recurseForDerivations = true' attribute. */
@@ -396,9 +400,10 @@ static void getDerivations(EvalState& state, Value& vIn,
           Bindings::iterator j = i->value->attrs->find(
               state.symbols.create("recurseForDerivations"));
           if (j != i->value->attrs->end() &&
-              state.forceBool(*j->value, *j->pos))
+              state.forceBool(*j->value, *j->pos)) {
             getDerivations(state, *i->value, pathPrefix2, autoArgs, drvs, done,
                            ignoreAssertionFailures);
+          }
         }
       }
     }
@@ -408,9 +413,10 @@ static void getDerivations(EvalState& state, Value& vIn,
     for (unsigned int n = 0; n < v.listSize(); ++n) {
       string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
       if (getDerivation(state, *v.listElems()[n], pathPrefix2, drvs, done,
-                        ignoreAssertionFailures))
+                        ignoreAssertionFailures)) {
         getDerivations(state, *v.listElems()[n], pathPrefix2, autoArgs, drvs,
                        done, ignoreAssertionFailures);
+      }
     }
   }
 
diff --git a/third_party/nix/src/libexpr/json-to-value.cc b/third_party/nix/src/libexpr/json-to-value.cc
index 51d001d8a5..70628636e1 100644
--- a/third_party/nix/src/libexpr/json-to-value.cc
+++ b/third_party/nix/src/libexpr/json-to-value.cc
@@ -21,29 +21,30 @@ static string parseJSONString(const char*& s) {
     }
     if (*s == '\\') {
       s++;
-      if (*s == '"')
+      if (*s == '"') {
         res += '"';
-      else if (*s == '\\')
+      } else if (*s == '\\') {
         res += '\\';
-      else if (*s == '/')
+      } else if (*s == '/') {
         res += '/';
-      else if (*s == '/')
+      } else if (*s == '/') {
         res += '/';
-      else if (*s == 'b')
+      } else if (*s == 'b') {
         res += '\b';
-      else if (*s == 'f')
+      } else if (*s == 'f') {
         res += '\f';
-      else if (*s == 'n')
+      } else if (*s == 'n') {
         res += '\n';
-      else if (*s == 'r')
+      } else if (*s == 'r') {
         res += '\r';
-      else if (*s == 't')
+      } else if (*s == 't') {
         res += '\t';
-      else if (*s == 'u')
+      } else if (*s == 'u') {
         throw JSONParseError(
             "\\u characters in JSON strings are currently not supported");
-      else
+      } else {
         throw JSONParseError("invalid escaped character in JSON string");
+      }
       s++;
     } else {
       res += *s++;
@@ -76,8 +77,9 @@ static void parseJSON(EvalState& state, const char*& s, Value& v) {
       if (*s == ']') {
         break;
       }
-      if (*s != ',')
+      if (*s != ',') {
         throw JSONParseError("expected ',' or ']' after JSON array element");
+      }
       s++;
     }
     s++;
@@ -108,8 +110,9 @@ static void parseJSON(EvalState& state, const char*& s, Value& v) {
       if (*s == '}') {
         break;
       }
-      if (*s != ',')
+      if (*s != ',') {
         throw JSONParseError("expected ',' or '}' after JSON member");
+      }
       s++;
     }
     state.mkAttrs(v, attrs.size());
@@ -137,10 +140,11 @@ static void parseJSON(EvalState& state, const char*& s, Value& v) {
     }
 
     try {
-      if (number_type == tFloat)
+      if (number_type == tFloat) {
         mkFloat(v, stod(tmp_number));
-      else
+      } else {
         mkInt(v, stol(tmp_number));
+      }
     } catch (std::invalid_argument& e) {
       throw JSONParseError("invalid JSON number");
     } catch (std::out_of_range& e) {
@@ -163,17 +167,19 @@ static void parseJSON(EvalState& state, const char*& s, Value& v) {
     mkNull(v);
   }
 
-  else
+  else {
     throw JSONParseError("unrecognised JSON value");
+  }
 }
 
 void parseJSON(EvalState& state, const string& s_, Value& v) {
   const char* s = s_.c_str();
   parseJSON(state, s, v);
   skipWhitespace(s);
-  if (*s)
+  if (*s) {
     throw JSONParseError(
         format("expected end-of-string while parsing JSON value: %1%") % s);
+  }
 }
 
 }  // namespace nix
diff --git a/third_party/nix/src/libexpr/names.cc b/third_party/nix/src/libexpr/names.cc
index f83ed9fe64..184f30999e 100644
--- a/third_party/nix/src/libexpr/names.cc
+++ b/third_party/nix/src/libexpr/names.cc
@@ -25,9 +25,10 @@ DrvName::DrvName(const string& s) : hits(0) {
 
 bool DrvName::matches(DrvName& n) {
   if (name != "*") {
-    if (!regex)
+    if (!regex) {
       regex = std::unique_ptr<std::regex>(
           new std::regex(name, std::regex::extended));
+    }
     if (!std::regex_match(n.name, *regex)) {
       return false;
     }
@@ -41,7 +42,9 @@ bool DrvName::matches(DrvName& n) {
 string nextComponent(string::const_iterator& p,
                      const string::const_iterator end) {
   /* Skip any dots and dashes (component separators). */
-  while (p != end && (*p == '.' || *p == '-')) ++p;
+  while (p != end && (*p == '.' || *p == '-')) {
+    ++p;
+  }
 
   if (p == end) {
     return "";
@@ -51,10 +54,15 @@ string nextComponent(string::const_iterator& p,
      of digits.  Otherwise, consume the longest sequence of
      non-digit, non-separator characters. */
   string s;
-  if (isdigit(*p))
-    while (p != end && isdigit(*p)) s += *p++;
-  else
-    while (p != end && (!isdigit(*p) && *p != '.' && *p != '-')) s += *p++;
+  if (isdigit(*p)) {
+    while (p != end && isdigit(*p)) {
+      s += *p++;
+    }
+  } else {
+    while (p != end && (!isdigit(*p) && *p != '.' && *p != '-')) {
+      s += *p++;
+    }
+  }
 
   return s;
 }
@@ -65,14 +73,14 @@ static bool componentsLT(const string& c1, const string& c2) {
 
   if (c1Num && c2Num) {
     return n1 < n2;
-  } else if (c1 == "" && c2Num)
+  } else if (c1 == "" && c2Num) {
     return true;
-  else if (c1 == "pre" && c2 != "pre")
+  } else if (c1 == "pre" && c2 != "pre") {
     return true;
-  else if (c2 == "pre")
+  } else if (c2 == "pre") {
     return false;
-  /* Assume that `2.3a' < `2.3.1'. */
-  else if (c2Num) {
+    /* Assume that `2.3a' < `2.3.1'. */
+  } else if (c2Num) {
     return true;
   } else if (c1Num) {
     return false;
@@ -88,10 +96,11 @@ int compareVersions(const string& v1, const string& v2) {
   while (p1 != v1.end() || p2 != v2.end()) {
     string c1 = nextComponent(p1, v1.end());
     string c2 = nextComponent(p2, v2.end());
-    if (componentsLT(c1, c2))
+    if (componentsLT(c1, c2)) {
       return -1;
-    else if (componentsLT(c2, c1))
+    } else if (componentsLT(c2, c1)) {
       return 1;
+    }
   }
 
   return 0;
diff --git a/third_party/nix/src/libexpr/nixexpr.cc b/third_party/nix/src/libexpr/nixexpr.cc
index bd171f8166..dc2c2b75e3 100644
--- a/third_party/nix/src/libexpr/nixexpr.cc
+++ b/third_party/nix/src/libexpr/nixexpr.cc
@@ -16,37 +16,40 @@ std::ostream& operator<<(std::ostream& str, const Expr& e) {
 
 static void showString(std::ostream& str, const string& s) {
   str << '"';
-  for (auto c : (string)s)
-    if (c == '"' || c == '\\' || c == '$')
+  for (auto c : (string)s) {
+    if (c == '"' || c == '\\' || c == '$') {
       str << "\\" << c;
-    else if (c == '\n')
+    } else if (c == '\n') {
       str << "\\n";
-    else if (c == '\r')
+    } else if (c == '\r') {
       str << "\\r";
-    else if (c == '\t')
+    } else if (c == '\t') {
       str << "\\t";
-    else
+    } else {
       str << c;
+    }
+  }
   str << '"';
 }
 
 static void showId(std::ostream& str, const string& s) {
-  if (s.empty())
+  if (s.empty()) {
     str << "\"\"";
-  else if (s == "if")  // FIXME: handle other keywords
+  } else if (s == "if") {  // FIXME: handle other keywords
     str << '"' << s << '"';
-  else {
+  } else {
     char c = s[0];
     if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) {
       showString(str, s);
       return;
     }
-    for (auto c : s)
+    for (auto c : s) {
       if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
             (c >= '0' && c <= '9') || c == '_' || c == '\'' || c == '-')) {
         showString(str, s);
         return;
       }
+    }
     str << s;
   }
 }
@@ -84,14 +87,17 @@ void ExprAttrs::show(std::ostream& str) const {
     str << "rec ";
   }
   str << "{ ";
-  for (auto& i : attrs)
-    if (i.second.inherited)
+  for (auto& i : attrs) {
+    if (i.second.inherited) {
       str << "inherit " << i.first << " "
           << "; ";
-    else
+    } else {
       str << i.first << " = " << *i.second.e << "; ";
-  for (auto& i : dynamicAttrs)
+    }
+  }
+  for (auto& i : dynamicAttrs) {
     str << "\"${" << *i.nameExpr << "}\" = " << *i.valueExpr << "; ";
+  }
   str << "}";
 }
 
@@ -109,10 +115,11 @@ void ExprLambda::show(std::ostream& str) const {
     str << "{ ";
     bool first = true;
     for (auto& i : formals->formals) {
-      if (first)
+      if (first) {
         first = false;
-      else
+      } else {
         str << ", ";
+      }
       str << i.name;
       if (i.def) {
         str << " ? " << *i.def;
@@ -137,11 +144,13 @@ void ExprLambda::show(std::ostream& str) const {
 
 void ExprLet::show(std::ostream& str) const {
   str << "(let ";
-  for (auto& i : attrs->attrs)
+  for (auto& i : attrs->attrs) {
     if (i.second.inherited) {
       str << "inherit " << i.first << "; ";
-    } else
+    } else {
       str << i.first << " = " << *i.second.e << "; ";
+    }
+  }
   str << "in " << *body << ")";
 }
 
@@ -163,10 +172,11 @@ void ExprConcatStrings::show(std::ostream& str) const {
   bool first = true;
   str << "(";
   for (auto& i : *es) {
-    if (first)
+    if (first) {
       first = false;
-    else
+    } else {
       str << " + ";
+    }
     str << *i;
   }
   str << ")";
@@ -175,12 +185,13 @@ void ExprConcatStrings::show(std::ostream& str) const {
 void ExprPos::show(std::ostream& str) const { str << "__curPos"; }
 
 std::ostream& operator<<(std::ostream& str, const Pos& pos) {
-  if (!pos)
+  if (!pos) {
     str << "undefined position";
-  else
+  } else {
     str << (format(ANSI_BOLD "%1%" ANSI_NORMAL ":%2%:%3%") % (string)pos.file %
             pos.line % pos.column)
                .str();
+  }
   return str;
 }
 
@@ -188,14 +199,16 @@ string showAttrPath(const AttrPath& attrPath) {
   std::ostringstream out;
   bool first = true;
   for (auto& i : attrPath) {
-    if (!first)
+    if (!first) {
       out << '.';
-    else
+    } else {
       first = false;
-    if (i.symbol.set())
+    }
+    if (i.symbol.set()) {
       out << i.symbol;
-    else
+    } else {
       out << "\"${" << *i.expr << "}\"";
+    }
   }
   return out.str();
 }
@@ -239,9 +252,10 @@ void ExprVar::bindVars(const StaticEnv& env) {
   /* Otherwise, the variable must be obtained from the nearest
      enclosing `with'.  If there is no `with', then we can issue an
      "undefined variable" error now. */
-  if (withLevel == -1)
+  if (withLevel == -1) {
     throw UndefinedVarError(format("undefined variable '%1%' at %2%") % name %
                             pos);
+  }
 
   fromWith = true;
   this->level = withLevel;
@@ -252,18 +266,20 @@ void ExprSelect::bindVars(const StaticEnv& env) {
   if (def) {
     def->bindVars(env);
   }
-  for (auto& i : attrPath)
+  for (auto& i : attrPath) {
     if (!i.symbol.set()) {
       i.expr->bindVars(env);
     }
+  }
 }
 
 void ExprOpHasAttr::bindVars(const StaticEnv& env) {
   e->bindVars(env);
-  for (auto& i : attrPath)
+  for (auto& i : attrPath) {
     if (!i.symbol.set()) {
       i.expr->bindVars(env);
     }
+  }
 }
 
 void ExprAttrs::bindVars(const StaticEnv& env) {
@@ -315,10 +331,11 @@ void ExprLambda::bindVars(const StaticEnv& env) {
       newEnv.vars[i.name] = displ++;
     }
 
-    for (auto& i : formals->formals)
+    for (auto& i : formals->formals) {
       if (i.def) {
         i.def->bindVars(newEnv);
       }
+    }
   }
 
   body->bindVars(newEnv);
@@ -332,8 +349,9 @@ void ExprLet::bindVars(const StaticEnv& env) {
     newEnv.vars[i.first] = i.second.displ = displ++;
   }
 
-  for (auto& i : attrs->attrs)
+  for (auto& i : attrs->attrs) {
     i.second.e->bindVars(i.second.inherited ? env : newEnv);
+  }
 
   body->bindVars(newEnv);
 }
diff --git a/third_party/nix/src/libexpr/primops.cc b/third_party/nix/src/libexpr/primops.cc
index 850d17a8f4..6835f03c8b 100644
--- a/third_party/nix/src/libexpr/primops.cc
+++ b/third_party/nix/src/libexpr/primops.cc
@@ -37,8 +37,9 @@ std::pair<string, string> decodeContext(const string& s) {
     size_t index = s.find("!", 1);
     return std::pair<string, string>(string(s, index + 1),
                                      string(s, 1, index - 1));
-  } else
+  } else {
     return std::pair<string, string>(s.at(0) == '/' ? s : string(s, 1), "");
+  }
 }
 
 InvalidPathError::InvalidPathError(const Path& path)
@@ -62,9 +63,10 @@ void EvalState::realiseContext(const PathSet& context) {
       if (allowedPaths) {
         auto drv = store->derivationFromPath(decoded.first);
         DerivationOutputs::iterator i = drv.outputs.find(decoded.second);
-        if (i == drv.outputs.end())
+        if (i == drv.outputs.end()) {
           throw Error("derivation '%s' does not have an output named '%s'",
                       decoded.first, decoded.second);
+        }
         allowedPaths->insert(i->second.path);
       }
     }
@@ -74,10 +76,11 @@ void EvalState::realiseContext(const PathSet& context) {
     return;
   }
 
-  if (!evalSettings.enableImportFromDerivation)
+  if (!evalSettings.enableImportFromDerivation) {
     throw EvalError(format("attempted to realize '%1%' during evaluation but "
                            "'allow-import-from-derivation' is false") %
                     *(drvs.begin()));
+  }
 
   /* For performance, prefetch all substitute info. */
   PathSet willBuild, willSubstitute, unknown;
@@ -178,20 +181,22 @@ void prim_importNative(EvalState& state, const Pos& pos, Value** args,
   string sym = state.forceStringNoCtx(*args[1], pos);
 
   void* handle = dlopen(path.c_str(), RTLD_LAZY | RTLD_LOCAL);
-  if (!handle)
+  if (!handle) {
     throw EvalError(format("could not open '%1%': %2%") % path % dlerror());
+  }
 
   dlerror();
   ValueInitializer func = (ValueInitializer)dlsym(handle, sym.c_str());
   if (!func) {
     char* message = dlerror();
-    if (message)
+    if (message) {
       throw EvalError(format("could not load symbol '%1%' from '%2%': %3%") %
                       sym % path % message);
-    else
+    } else {
       throw EvalError(format("symbol '%1%' from '%2%' resolved to NULL when a "
                              "function pointer was expected") %
                       sym % path);
+    }
   }
 
   (func)(state, v);
@@ -356,9 +361,10 @@ struct CompareValues {
     if (v1->type == tInt && v2->type == tFloat) {
       return v1->integer < v2->fpoint;
     }
-    if (v1->type != v2->type)
+    if (v1->type != v2->type) {
       throw EvalError(format("cannot compare %1% with %2%") % showType(*v1) %
                       showType(*v2));
+    }
     switch (v1->type) {
       case tInt:
         return v1->integer < v2->integer;
@@ -388,19 +394,22 @@ static void prim_genericClosure(EvalState& state, const Pos& pos, Value** args,
   /* Get the start set. */
   Bindings::iterator startSet =
       args[0]->attrs->find(state.symbols.create("startSet"));
-  if (startSet == args[0]->attrs->end())
+  if (startSet == args[0]->attrs->end()) {
     throw EvalError(format("attribute 'startSet' required, at %1%") % pos);
+  }
   state.forceList(*startSet->value, pos);
 
   ValueList workSet;
-  for (unsigned int n = 0; n < startSet->value->listSize(); ++n)
+  for (unsigned int n = 0; n < startSet->value->listSize(); ++n) {
     workSet.push_back(startSet->value->listElems()[n]);
+  }
 
   /* Get the operator. */
   Bindings::iterator op =
       args[0]->attrs->find(state.symbols.create("operator"));
-  if (op == args[0]->attrs->end())
+  if (op == args[0]->attrs->end()) {
     throw EvalError(format("attribute 'operator' required, at %1%") % pos);
+  }
   state.forceValue(*op->value);
 
   /* Construct the closure by applying the operator to element of
@@ -417,8 +426,9 @@ static void prim_genericClosure(EvalState& state, const Pos& pos, Value** args,
     state.forceAttrs(*e, pos);
 
     Bindings::iterator key = e->attrs->find(state.symbols.create("key"));
-    if (key == e->attrs->end())
+    if (key == e->attrs->end()) {
       throw EvalError(format("attribute 'key' required, at %1%") % pos);
+    }
     state.forceValue(*key->value);
 
     if (doneKeys.find(key->value) != doneKeys.end()) {
@@ -551,8 +561,9 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
 
   /* Figure out the name first (for stack backtraces). */
   Bindings::iterator attr = args[0]->attrs->find(state.sName);
-  if (attr == args[0]->attrs->end())
+  if (attr == args[0]->attrs->end()) {
     throw EvalError(format("required attribute 'name' missing, at %1%") % pos);
+  }
   string drvName;
   Pos& posDrvName(*attr->pos);
   try {
@@ -568,8 +579,9 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
   std::ostringstream jsonBuf;
   std::unique_ptr<JSONObject> jsonObject;
   attr = args[0]->attrs->find(state.sStructuredAttrs);
-  if (attr != args[0]->attrs->end() && state.forceBool(*attr->value, pos))
+  if (attr != args[0]->attrs->end() && state.forceBool(*attr->value, pos)) {
     jsonObject = std::make_unique<JSONObject>(jsonBuf);
+  }
 
   /* Check whether null attributes should be ignored. */
   bool ignoreNulls = false;
@@ -597,37 +609,41 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
     const string& key = i->name;
 
     auto handleHashMode = [&](const std::string& s) {
-      if (s == "recursive")
+      if (s == "recursive") {
         outputHashRecursive = true;
-      else if (s == "flat")
+      } else if (s == "flat") {
         outputHashRecursive = false;
-      else
+      } else {
         throw EvalError(
             "invalid value '%s' for 'outputHashMode' attribute, at %s", s,
             posDrvName);
+      }
     };
 
     auto handleOutputs = [&](const Strings& ss) {
       outputs.clear();
       for (auto& j : ss) {
-        if (outputs.find(j) != outputs.end())
+        if (outputs.find(j) != outputs.end()) {
           throw EvalError(format("duplicate derivation output '%1%', at %2%") %
                           j % posDrvName);
+        }
         /* !!! Check whether j is a valid attribute
            name. */
         /* Derivations cannot be named ‘drv’, because
            then we'd have an attribute ‘drvPath’ in
            the resulting set. */
-        if (j == "drv")
+        if (j == "drv") {
           throw EvalError(
               format("invalid derivation output name 'drv', at %1%") %
               posDrvName);
+        }
         outputs.insert(j);
       }
-      if (outputs.empty())
+      if (outputs.empty()) {
         throw EvalError(
             format("derivation cannot have an empty set of outputs, at %1%") %
             posDrvName);
+      }
     };
 
     try {
@@ -660,41 +676,43 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
           auto placeholder(jsonObject->placeholder(key));
           printValueAsJSON(state, true, *i->value, placeholder, context);
 
-          if (i->name == state.sBuilder)
+          if (i->name == state.sBuilder) {
             drv.builder = state.forceString(*i->value, context, posDrvName);
-          else if (i->name == state.sSystem)
+          } else if (i->name == state.sSystem) {
             drv.platform = state.forceStringNoCtx(*i->value, posDrvName);
-          else if (i->name == state.sOutputHash)
+          } else if (i->name == state.sOutputHash) {
             outputHash = state.forceStringNoCtx(*i->value, posDrvName);
-          else if (i->name == state.sOutputHashAlgo)
+          } else if (i->name == state.sOutputHashAlgo) {
             outputHashAlgo = state.forceStringNoCtx(*i->value, posDrvName);
-          else if (i->name == state.sOutputHashMode)
+          } else if (i->name == state.sOutputHashMode) {
             handleHashMode(state.forceStringNoCtx(*i->value, posDrvName));
-          else if (i->name == state.sOutputs) {
+          } else if (i->name == state.sOutputs) {
             /* Require ‘outputs’ to be a list of strings. */
             state.forceList(*i->value, posDrvName);
             Strings ss;
-            for (unsigned int n = 0; n < i->value->listSize(); ++n)
+            for (unsigned int n = 0; n < i->value->listSize(); ++n) {
               ss.emplace_back(state.forceStringNoCtx(*i->value->listElems()[n],
                                                      posDrvName));
+            }
             handleOutputs(ss);
           }
 
         } else {
           auto s = state.coerceToString(posDrvName, *i->value, context, true);
           drv.env.emplace(key, s);
-          if (i->name == state.sBuilder)
+          if (i->name == state.sBuilder) {
             drv.builder = s;
-          else if (i->name == state.sSystem)
+          } else if (i->name == state.sSystem) {
             drv.platform = s;
-          else if (i->name == state.sOutputHash)
+          } else if (i->name == state.sOutputHash) {
             outputHash = s;
-          else if (i->name == state.sOutputHashAlgo)
+          } else if (i->name == state.sOutputHashAlgo) {
             outputHashAlgo = s;
-          else if (i->name == state.sOutputHashMode)
+          } else if (i->name == state.sOutputHashMode) {
             handleHashMode(s);
-          else if (i->name == state.sOutputs)
+          } else if (i->name == state.sOutputs) {
             handleOutputs(tokenizeString<Strings>(s));
+          }
         }
       }
 
@@ -728,8 +746,9 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
       state.store->computeFSClosure(string(path, 1), refs);
       for (auto& j : refs) {
         drv.inputSrcs.insert(j);
-        if (isDerivation(j))
+        if (isDerivation(j)) {
           drv.inputDrvs[j] = state.store->queryDerivationOutputNames(j);
+        }
       }
     }
 
@@ -740,31 +759,36 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
     }
 
     /* Otherwise it's a source file. */
-    else
+    else {
       drv.inputSrcs.insert(path);
+    }
   }
 
   /* Do we have all required attributes? */
-  if (drv.builder == "")
+  if (drv.builder == "") {
     throw EvalError(format("required attribute 'builder' missing, at %1%") %
                     posDrvName);
-  if (drv.platform == "")
+  }
+  if (drv.platform == "") {
     throw EvalError(format("required attribute 'system' missing, at %1%") %
                     posDrvName);
+  }
 
   /* Check whether the derivation name is valid. */
   checkStoreName(drvName);
-  if (isDerivation(drvName))
+  if (isDerivation(drvName)) {
     throw EvalError(
         format("derivation names are not allowed to end in '%1%', at %2%") %
         drvExtension % posDrvName);
+  }
 
   if (outputHash) {
     /* Handle fixed-output derivations. */
-    if (outputs.size() != 1 || *(outputs.begin()) != "out")
+    if (outputs.size() != 1 || *(outputs.begin()) != "out") {
       throw Error(format("multiple outputs are not supported in fixed-output "
                          "derivations, at %1%") %
                   posDrvName);
+    }
 
     HashType ht =
         outputHashAlgo.empty() ? htUnknown : parseHashType(outputHashAlgo);
@@ -797,7 +821,7 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
        path. */
     Hash h = hashDerivationModulo(*state.store, drv);
 
-    for (auto& i : drv.outputs)
+    for (auto& i : drv.outputs) {
       if (i.second.path == "") {
         Path outPath = state.store->makeOutputPath(i.first, h, drvName);
         if (!jsonObject) {
@@ -805,6 +829,7 @@ static void prim_derivationStrict(EvalState& state, const Pos& pos,
         }
         i.second.path = outPath;
       }
+    }
   }
 
   /* Write the resulting term into the Nix store directory. */
@@ -868,9 +893,10 @@ static void prim_storePath(EvalState& state, const Pos& pos, Value** args,
   if (!state.store->isStorePath(path)) {
     path = canonPath(path, true);
   }
-  if (!state.store->isInStore(path))
+  if (!state.store->isInStore(path)) {
     throw EvalError(format("path '%1%' is not in the Nix store, at %2%") %
                     path % pos);
+  }
   Path path2 = state.store->toStorePath(path);
   if (!settings.readOnlyMode) {
     state.store->ensurePath(path2);
@@ -939,10 +965,11 @@ static void prim_readFile(EvalState& state, const Pos& pos, Value** args,
         path % e.path % pos);
   }
   string s = readFile(state.checkSourcePath(state.toRealPath(path, context)));
-  if (s.find((char)0) != string::npos)
+  if (s.find((char)0) != string::npos) {
     throw Error(format("the contents of the file '%1%' cannot be represented "
                        "as a Nix string") %
                 path);
+  }
   mkString(v, s.c_str());
 }
 
@@ -965,8 +992,9 @@ static void prim_findFile(EvalState& state, const Pos& pos, Value** args,
     }
 
     i = v2.attrs->find(state.symbols.create("path"));
-    if (i == v2.attrs->end())
+    if (i == v2.attrs->end()) {
       throw EvalError(format("attribute 'path' missing, at %1%") % pos);
+    }
 
     PathSet context;
     string path = state.coerceToString(pos, *i->value, context, false, false);
@@ -993,8 +1021,9 @@ static void prim_hashFile(EvalState& state, const Pos& pos, Value** args,
                           Value& v) {
   string type = state.forceStringNoCtx(*args[0], pos);
   HashType ht = parseHashType(type);
-  if (ht == htUnknown)
+  if (ht == htUnknown) {
     throw Error(format("unknown hash type '%1%', at %2%") % type % pos);
+  }
 
   PathSet context;  // discarded
   Path p = state.coerceToPath(pos, *args[1], context);
@@ -1079,10 +1108,11 @@ static void prim_toFile(EvalState& state, const Pos& pos, Value** args,
   PathSet refs;
 
   for (auto path : context) {
-    if (path.at(0) != '/')
+    if (path.at(0) != '/') {
       throw EvalError(format("in 'toFile': the file '%1%' cannot refer to "
                              "derivation outputs, at %2%") %
                       name % pos);
+    }
     refs.insert(path);
   }
 
@@ -1150,8 +1180,9 @@ static void addPath(EvalState& state, const Pos& pos, const string& name,
                          "added from '%1%'") %
                   path);
     }
-  } else
+  } else {
     dstPath = expectedStorePath;
+  }
 
   mkString(v, dstPath, {dstPath});
 }
@@ -1160,15 +1191,17 @@ static void prim_filterSource(EvalState& state, const Pos& pos, Value** args,
                               Value& v) {
   PathSet context;
   Path path = state.coerceToPath(pos, *args[1], context);
-  if (!context.empty())
+  if (!context.empty()) {
     throw EvalError(format("string '%1%' cannot refer to other paths, at %2%") %
                     path % pos);
+  }
 
   state.forceValue(*args[0]);
-  if (args[0]->type != tLambda)
+  if (args[0]->type != tLambda) {
     throw TypeError(format("first argument in call to 'filterSource' is not a "
                            "function but %1%, at %2%") %
                     showType(*args[0]) % pos);
+  }
 
   addPath(state, pos, baseNameOf(path), path, args[0], true, Hash(), v);
 }
@@ -1187,24 +1220,26 @@ static void prim_path(EvalState& state, const Pos& pos, Value** args,
     if (n == "path") {
       PathSet context;
       path = state.coerceToPath(*attr.pos, *attr.value, context);
-      if (!context.empty())
+      if (!context.empty()) {
         throw EvalError(
             format("string '%1%' cannot refer to other paths, at %2%") % path %
             *attr.pos);
-    } else if (attr.name == state.sName)
+      }
+    } else if (attr.name == state.sName) {
       name = state.forceStringNoCtx(*attr.value, *attr.pos);
-    else if (n == "filter") {
+    } else if (n == "filter") {
       state.forceValue(*attr.value);
       filterFun = attr.value;
-    } else if (n == "recursive")
+    } else if (n == "recursive") {
       recursive = state.forceBool(*attr.value, *attr.pos);
-    else if (n == "sha256")
+    } else if (n == "sha256") {
       expectedHash =
           Hash(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256);
-    else
+    } else {
       throw EvalError(
           format("unsupported argument '%1%' to 'addPath', at %2%") %
           attr.name % *attr.pos);
+    }
   }
   if (path.empty()) {
     throw EvalError(format("'path' required, at %1%") % pos);
@@ -1229,8 +1264,9 @@ static void prim_attrNames(EvalState& state, const Pos& pos, Value** args,
   state.mkList(v, args[0]->attrs->size());
 
   size_t n = 0;
-  for (auto& i : *args[0]->attrs)
+  for (auto& i : *args[0]->attrs) {
     mkString(*(v.listElems()[n++] = state.allocValue()), i.name);
+  }
 
   std::sort(v.listElems(), v.listElems() + n, [](Value* v1, Value* v2) {
     return strcmp(v1->string.s, v2->string.s) < 0;
@@ -1265,8 +1301,9 @@ void prim_getAttr(EvalState& state, const Pos& pos, Value** args, Value& v) {
   state.forceAttrs(*args[1], pos);
   // !!! Should we create a symbol here or just do a lookup?
   Bindings::iterator i = args[1]->attrs->find(state.symbols.create(attr));
-  if (i == args[1]->attrs->end())
+  if (i == args[1]->attrs->end()) {
     throw EvalError(format("attribute '%1%' missing, at %2%") % attr % pos);
+  }
   // !!! add to stack trace?
   if (state.countCalls && i->pos) {
     state.attrSelects[*i->pos]++;
@@ -1345,21 +1382,23 @@ static void prim_listToAttrs(EvalState& state, const Pos& pos, Value** args,
     state.forceAttrs(v2, pos);
 
     Bindings::iterator j = v2.attrs->find(state.sName);
-    if (j == v2.attrs->end())
+    if (j == v2.attrs->end()) {
       throw TypeError(
           format(
               "'name' attribute missing in a call to 'listToAttrs', at %1%") %
           pos);
+    }
     string name = state.forceStringNoCtx(*j->value, pos);
 
     Symbol sym = state.symbols.create(name);
     if (seen.find(sym) == seen.end()) {
       Bindings::iterator j2 =
           v2.attrs->find(state.symbols.create(state.sValue));
-      if (j2 == v2.attrs->end())
+      if (j2 == v2.attrs->end()) {
         throw TypeError(format("'value' attribute missing in a call to "
                                "'listToAttrs', at %1%") %
                         pos);
+      }
 
       v.attrs->push_back(Attr(sym, j2->value, j2->pos));
       seen.insert(sym);
@@ -1434,8 +1473,9 @@ static void prim_catAttrs(EvalState& state, const Pos& pos, Value** args,
 static void prim_functionArgs(EvalState& state, const Pos& pos, Value** args,
                               Value& v) {
   state.forceValue(*args[0]);
-  if (args[0]->type != tLambda)
+  if (args[0]->type != tLambda) {
     throw TypeError(format("'functionArgs' requires a function, at %1%") % pos);
+  }
 
   if (!args[0]->lambda.fun->matchAttrs) {
     state.mkAttrs(v, 0);
@@ -1443,9 +1483,10 @@ static void prim_functionArgs(EvalState& state, const Pos& pos, Value** args,
   }
 
   state.mkAttrs(v, args[0]->lambda.fun->formals->formals.size());
-  for (auto& i : args[0]->lambda.fun->formals->formals)
+  for (auto& i : args[0]->lambda.fun->formals->formals) {
     // !!! should optimise booleans (allocate only once)
     mkBool(*state.allocAttr(v, i.name), i.def);
+  }
   v.attrs->sort();
 }
 
@@ -1479,8 +1520,9 @@ static void prim_isList(EvalState& state, const Pos& pos, Value** args,
 static void elemAt(EvalState& state, const Pos& pos, Value& list, int n,
                    Value& v) {
   state.forceList(list, pos);
-  if (n < 0 || (unsigned int)n >= list.listSize())
+  if (n < 0 || (unsigned int)n >= list.listSize()) {
     throw Error(format("list index %1% is out of bounds, at %2%") % n % pos);
+  }
   state.forceValue(*list.listElems()[n]);
   v = *list.listElems()[n];
 }
@@ -1503,8 +1545,9 @@ static void prim_head(EvalState& state, const Pos& pos, Value** args,
 static void prim_tail(EvalState& state, const Pos& pos, Value** args,
                       Value& v) {
   state.forceList(*args[0], pos);
-  if (args[0]->listSize() == 0)
+  if (args[0]->listSize() == 0) {
     throw Error(format("'tail' called on an empty list, at %1%") % pos);
+  }
   state.mkList(v, args[0]->listSize() - 1);
   for (unsigned int n = 0; n < v.listSize(); ++n) {
     v.listElems()[n] = args[0]->listElems()[n + 1];
@@ -1637,9 +1680,10 @@ static void prim_genList(EvalState& state, const Pos& pos, Value** args,
                          Value& v) {
   auto len = state.forceInt(*args[1], pos);
 
-  if (len < 0)
+  if (len < 0) {
     throw EvalError(format("cannot create list of size %1%, at %2%") % len %
                     pos);
+  }
 
   state.mkList(v, len);
 
@@ -1698,10 +1742,11 @@ static void prim_partition(EvalState& state, const Pos& pos, Value** args,
     state.forceValue(*vElem);
     Value res;
     state.callFunction(*args[0], *vElem, res, pos);
-    if (state.forceBool(res, pos))
+    if (state.forceBool(res, pos)) {
       right.push_back(vElem);
-    else
+    } else {
       wrong.push_back(vElem);
+    }
   }
 
   state.mkAttrs(v, 2);
@@ -1805,8 +1850,9 @@ static void prim_div(EvalState& state, const Pos& pos, Value** args, Value& v) {
     NixInt i1 = state.forceInt(*args[0], pos);
     NixInt i2 = state.forceInt(*args[1], pos);
     /* Avoid division overflow as it might raise SIGFPE. */
-    if (i1 == std::numeric_limits<NixInt>::min() && i2 == -1)
+    if (i1 == std::numeric_limits<NixInt>::min() && i2 == -1) {
       throw EvalError(format("overflow in integer division, at %1%") % pos);
+    }
     mkInt(v, i1 / i2);
   }
 }
@@ -1859,9 +1905,10 @@ static void prim_substring(EvalState& state, const Pos& pos, Value** args,
   PathSet context;
   string s = state.coerceToString(pos, *args[2], context);
 
-  if (start < 0)
+  if (start < 0) {
     throw EvalError(format("negative start position in 'substring', at %1%") %
                     pos);
+  }
 
   mkString(v, (unsigned int)start >= s.size() ? "" : string(s, start, len),
            context);
@@ -1879,8 +1926,9 @@ static void prim_hashString(EvalState& state, const Pos& pos, Value** args,
                             Value& v) {
   string type = state.forceStringNoCtx(*args[0], pos);
   HashType ht = parseHashType(type);
-  if (ht == htUnknown)
+  if (ht == htUnknown) {
     throw Error(format("unknown hash type '%1%', at %2%") % type % pos);
+  }
 
   PathSet context;  // discarded
   string s = state.forceString(*args[1], context, pos);
@@ -1910,11 +1958,12 @@ static void prim_match(EvalState& state, const Pos& pos, Value** args,
     const size_t len = match.size() - 1;
     state.mkList(v, len);
     for (size_t i = 0; i < len; ++i) {
-      if (!match[i + 1].matched)
+      if (!match[i + 1].matched) {
         mkNull(*(v.listElems()[i] = state.allocValue()));
-      else
+      } else {
         mkString(*(v.listElems()[i] = state.allocValue()),
                  match[i + 1].str().c_str());
+      }
     }
 
   } catch (std::regex_error& e) {
@@ -1969,11 +2018,12 @@ static void prim_split(EvalState& state, const Pos& pos, Value** args,
       // Start at 1, beacause the first match is the whole string.
       state.mkList(*elem, slen);
       for (size_t si = 0; si < slen; ++si) {
-        if (!match[si + 1].matched)
+        if (!match[si + 1].matched) {
           mkNull(*(elem->listElems()[si] = state.allocValue()));
-        else
+        } else {
           mkString(*(elem->listElems()[si] = state.allocValue()),
                    match[si + 1].str().c_str());
+        }
       }
 
       // Add a string for non-matched suffix characters.
@@ -2023,15 +2073,17 @@ static void prim_replaceStrings(EvalState& state, const Pos& pos, Value** args,
                                 Value& v) {
   state.forceList(*args[0], pos);
   state.forceList(*args[1], pos);
-  if (args[0]->listSize() != args[1]->listSize())
+  if (args[0]->listSize() != args[1]->listSize()) {
     throw EvalError(format("'from' and 'to' arguments to 'replaceStrings' have "
                            "different lengths, at %1%") %
                     pos);
+  }
 
   vector<string> from;
   from.reserve(args[0]->listSize());
-  for (unsigned int n = 0; n < args[0]->listSize(); ++n)
+  for (unsigned int n = 0; n < args[0]->listSize(); ++n) {
     from.push_back(state.forceString(*args[0]->listElems()[n], pos));
+  }
 
   vector<std::pair<string, PathSet>> to;
   to.reserve(args[1]->listSize());
@@ -2051,7 +2103,7 @@ static void prim_replaceStrings(EvalState& state, const Pos& pos, Value** args,
     bool found = false;
     auto i = from.begin();
     auto j = to.begin();
-    for (; i != from.end(); ++i, ++j)
+    for (; i != from.end(); ++i, ++j) {
       if (s.compare(p, i->size(), *i) == 0) {
         found = true;
         res += j->first;
@@ -2069,6 +2121,7 @@ static void prim_replaceStrings(EvalState& state, const Pos& pos, Value** args,
         j->second.clear();
         break;
       }
+    }
     if (!found) {
       if (p < s.size()) {
         res += s[p];
@@ -2139,20 +2192,22 @@ void fetch(EvalState& state, const Pos& pos, Value** args, Value& v,
 
     for (auto& attr : *args[0]->attrs) {
       string n(attr.name);
-      if (n == "url")
+      if (n == "url") {
         request.uri = state.forceStringNoCtx(*attr.value, *attr.pos);
-      else if (n == "sha256")
+      } else if (n == "sha256") {
         request.expectedHash =
             Hash(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256);
-      else if (n == "name")
+      } else if (n == "name") {
         request.name = state.forceStringNoCtx(*attr.value, *attr.pos);
-      else
+      } else {
         throw EvalError(format("unsupported argument '%1%' to '%2%', at %3%") %
                         attr.name % who % attr.pos);
+      }
     }
 
-    if (request.uri.empty())
+    if (request.uri.empty()) {
       throw EvalError(format("'url' argument required, at %1%") % pos);
+    }
 
   } else {
     request.uri = state.forceStringNoCtx(*args[0], pos);
@@ -2160,9 +2215,10 @@ void fetch(EvalState& state, const Pos& pos, Value** args, Value& v,
 
   state.checkURI(request.uri);
 
-  if (evalSettings.pureEval && !request.expectedHash)
+  if (evalSettings.pureEval && !request.expectedHash) {
     throw Error("in pure evaluation mode, '%s' requires a 'sha256' argument",
                 who);
+  }
 
   auto res = getDownloader()->downloadCached(state.store, request);
 
@@ -2282,10 +2338,11 @@ void EvalState::createBaseEnv() {
 
   // Paths
   addPrimOp("__toPath", 1, prim_toPath);
-  if (evalSettings.pureEval)
+  if (evalSettings.pureEval) {
     addPurityError("__storePath");
-  else
+  } else {
     addPrimOp("__storePath", 1, prim_storePath);
+  }
   addPrimOp("__pathExists", 1, prim_pathExists);
   addPrimOp("baseNameOf", 1, prim_baseNameOf);
   addPrimOp("dirOf", 1, prim_dirOf);
@@ -2387,9 +2444,11 @@ void EvalState::createBaseEnv() {
   }
   addConstant("__nixPath", v);
 
-  if (RegisterPrimOp::primOps)
-    for (auto& primOp : *RegisterPrimOp::primOps)
+  if (RegisterPrimOp::primOps) {
+    for (auto& primOp : *RegisterPrimOp::primOps) {
       addPrimOp(std::get<0>(primOp), std::get<1>(primOp), std::get<2>(primOp));
+    }
+  }
 
   /* Now that we've added all primops, sort the `builtins' set,
      because attribute lookups expect it to be sorted. */
diff --git a/third_party/nix/src/libexpr/value-to-json.cc b/third_party/nix/src/libexpr/value-to-json.cc
index e4f1c28537..eaf0fca3d3 100644
--- a/third_party/nix/src/libexpr/value-to-json.cc
+++ b/third_party/nix/src/libexpr/value-to-json.cc
@@ -58,8 +58,9 @@ void printValueAsJSON(EvalState& state, bool strict, Value& v,
           auto placeholder(obj.placeholder(j));
           printValueAsJSON(state, strict, *a.value, placeholder, context);
         }
-      } else
+      } else {
         printValueAsJSON(state, strict, *i->value, out, context);
+      }
       break;
     }
 
diff --git a/third_party/nix/src/libexpr/value-to-xml.cc b/third_party/nix/src/libexpr/value-to-xml.cc
index a03924aa63..44dede4875 100644
--- a/third_party/nix/src/libexpr/value-to-xml.cc
+++ b/third_party/nix/src/libexpr/value-to-xml.cc
@@ -94,8 +94,9 @@ static void printValueAsXML(EvalState& state, bool strict, bool location,
           if (strict) {
             state.forceValue(*a->value);
           }
-          if (a->value->type == tString)
+          if (a->value->type == tString) {
             xmlAttrs["drvPath"] = drvPath = a->value->string.s;
+          }
         }
 
         a = v.attrs->find(state.sOutPath);
@@ -103,8 +104,9 @@ static void printValueAsXML(EvalState& state, bool strict, bool location,
           if (strict) {
             state.forceValue(*a->value);
           }
-          if (a->value->type == tString)
+          if (a->value->type == tString) {
             xmlAttrs["outPath"] = a->value->string.s;
+          }
         }
 
         XMLOpenElement _(doc, "derivation", xmlAttrs);
@@ -112,8 +114,9 @@ static void printValueAsXML(EvalState& state, bool strict, bool location,
         if (drvPath != "" && drvsSeen.find(drvPath) == drvsSeen.end()) {
           drvsSeen.insert(drvPath);
           showAttrs(state, strict, location, *v.attrs, doc, context, drvsSeen);
-        } else
+        } else {
           doc.writeEmptyElement("repeated");
+        }
       }
 
       else {
diff --git a/third_party/nix/src/libmain/shared.cc b/third_party/nix/src/libmain/shared.cc
index 3df83733ad..332bd5c4ca 100644
--- a/third_party/nix/src/libmain/shared.cc
+++ b/third_party/nix/src/libmain/shared.cc
@@ -233,7 +233,9 @@ bool LegacyArgs::processFlag(Strings::iterator& pos, Strings::iterator end) {
     return true;
   }
   bool res = parseArg(pos, end);
-  if (res) ++pos;
+  if (res) {
+    ++pos;
+  }
   return res;
 }
 
@@ -244,8 +246,9 @@ bool LegacyArgs::processArgs(const Strings& args, bool finish) {
   assert(args.size() == 1);
   Strings ss(args);
   auto pos = ss.begin();
-  if (!parseArg(pos, ss.end()))
+  if (!parseArg(pos, ss.end())) {
     throw UsageError(format("unexpected argument '%1%'") % args.front());
+  }
   return true;
 }
 
@@ -346,8 +349,9 @@ RunPager::RunPager() {
   toPager.create();
 
   pid = startProcess([&]() {
-    if (dup2(toPager.readSide.get(), STDIN_FILENO) == -1)
+    if (dup2(toPager.readSide.get(), STDIN_FILENO) == -1) {
       throw SysError("dupping stdin");
+    }
     if (!getenv("LESS")) {
       setenv("LESS", "FRSXMK", 1);
     }
@@ -363,8 +367,9 @@ RunPager::RunPager() {
 
   pid.setKillSignal(SIGINT);
 
-  if (dup2(toPager.writeSide.get(), STDOUT_FILENO) == -1)
+  if (dup2(toPager.writeSide.get(), STDOUT_FILENO) == -1) {
     throw SysError("dupping stdout");
+  }
 }
 
 RunPager::~RunPager() {
diff --git a/third_party/nix/src/libmain/stack.cc b/third_party/nix/src/libmain/stack.cc
index 0d5b91c163..27c16f5d1f 100644
--- a/third_party/nix/src/libmain/stack.cc
+++ b/third_party/nix/src/libmain/stack.cc
@@ -58,8 +58,9 @@ void detectStackOverflow() {
     throw Error("cannot allocate alternative stack");
   }
   stack.ss_flags = 0;
-  if (sigaltstack(&stack, 0) == -1)
+  if (sigaltstack(&stack, 0) == -1) {
     throw SysError("cannot set alternative stack");
+  }
 
   struct sigaction act;
   sigfillset(&act.sa_mask);
diff --git a/third_party/nix/src/libstore/binary-cache-store.cc b/third_party/nix/src/libstore/binary-cache-store.cc
index 625ea1e11e..10a0ddfc13 100644
--- a/third_party/nix/src/libstore/binary-cache-store.cc
+++ b/third_party/nix/src/libstore/binary-cache-store.cc
@@ -19,9 +19,10 @@
 namespace nix {
 
 BinaryCacheStore::BinaryCacheStore(const Params& params) : Store(params) {
-  if (secretKeyFile != "")
+  if (secretKeyFile != "") {
     secretKey =
         std::unique_ptr<SecretKey>(new SecretKey(readFile(secretKeyFile)));
+  }
 
   StringSink sink;
   sink << narVersionMagic1;
@@ -44,10 +45,11 @@ void BinaryCacheStore::init() {
       auto name = line.substr(0, colon);
       auto value = trim(line.substr(colon + 1, std::string::npos));
       if (name == "StoreDir") {
-        if (value != storeDir)
+        if (value != storeDir) {
           throw Error(format("binary cache '%s' is for Nix stores with prefix "
                              "'%s', not '%s'") %
                       getUri() % value % storeDir);
+        }
       } else if (name == "WantMassQuery") {
         wantMassQuery_ = value == "1";
       } else if (name == "Priority") {
@@ -108,9 +110,10 @@ void BinaryCacheStore::writeNarInfo(ref<NarInfo> narInfo) {
     state_->pathInfoCache.upsert(hashPart, std::shared_ptr<NarInfo>(narInfo));
   }
 
-  if (diskCache)
+  if (diskCache) {
     diskCache->upsertNarInfo(getUri(), hashPart,
                              std::shared_ptr<NarInfo>(narInfo));
+  }
 }
 
 void BinaryCacheStore::addToStore(const ValidPathInfo& info,
@@ -123,7 +126,8 @@ void BinaryCacheStore::addToStore(const ValidPathInfo& info,
 
   /* Verify that all references are valid. This may do some .narinfo
      reads, but typically they'll already be cached. */
-  for (auto& ref : info.references) try {
+  for (auto& ref : info.references) {
+    try {
       if (ref != info.path) {
         queryPathInfo(ref);
       }
@@ -132,6 +136,7 @@ void BinaryCacheStore::addToStore(const ValidPathInfo& info,
                          "reference '%s' is not valid") %
                   info.path % ref);
     }
+  }
 
   assert(nar->compare(0, narMagic.size(), narMagic) == 0);
 
@@ -140,10 +145,11 @@ void BinaryCacheStore::addToStore(const ValidPathInfo& info,
   narInfo->narSize = nar->size();
   narInfo->narHash = hashString(htSHA256, *nar);
 
-  if (info.narHash && info.narHash != narInfo->narHash)
+  if (info.narHash && info.narHash != narInfo->narHash) {
     throw Error(
         format("refusing to copy corrupted path '%1%' to binary cache") %
         info.path);
+  }
 
   auto accessor_ = std::dynamic_pointer_cast<RemoteFSAccessor>(accessor);
 
@@ -203,8 +209,9 @@ void BinaryCacheStore::addToStore(const ValidPathInfo& info,
   if (repair || !fileExists(narInfo->url)) {
     stats.narWrite++;
     upsertFile(narInfo->url, *narCompressed, "application/x-nix-nar");
-  } else
+  } else {
     stats.narWriteAverted++;
+  }
 
   stats.narWriteBytes += nar->size();
   stats.narWriteCompressedBytes += narCompressed->size();
@@ -349,9 +356,9 @@ void BinaryCacheStore::addSignatures(const Path& storePath,
 std::shared_ptr<std::string> BinaryCacheStore::getBuildLog(const Path& path) {
   Path drvPath;
 
-  if (isDerivation(path))
+  if (isDerivation(path)) {
     drvPath = path;
-  else {
+  } else {
     try {
       auto info = queryPathInfo(path);
       // FIXME: add a "Log" field to .narinfo
diff --git a/third_party/nix/src/libstore/build.cc b/third_party/nix/src/libstore/build.cc
index 7aa44b4755..b1f63a4fac 100644
--- a/third_party/nix/src/libstore/build.cc
+++ b/third_party/nix/src/libstore/build.cc
@@ -333,10 +333,11 @@ class Worker {
 void addToWeakGoals(WeakGoals& goals, GoalPtr p) {
   // FIXME: necessary?
   // FIXME: O(n)
-  for (auto& i : goals)
+  for (auto& i : goals) {
     if (i.lock() == p) {
       return;
     }
+  }
   goals.push_back(p);
 }
 
@@ -369,10 +370,11 @@ void Goal::waiteeDone(GoalPtr waitee, ExitCode result) {
        remaining waitees. */
     for (auto& goal : waitees) {
       WeakGoals waiters2;
-      for (auto& j : goal->waiters)
+      for (auto& j : goal->waiters) {
         if (j.lock() != shared_from_this()) {
           waiters2.push_back(j);
         }
+      }
       goal->waiters = waiters2;
     }
     waitees.clear();
@@ -416,19 +418,23 @@ static void commonChildInit(Pipe& logPipe) {
   }
 
   /* Dup the write side of the logger pipe into stderr. */
-  if (dup2(logPipe.writeSide.get(), STDERR_FILENO) == -1)
+  if (dup2(logPipe.writeSide.get(), STDERR_FILENO) == -1) {
     throw SysError("cannot pipe standard error into log file");
+  }
 
   /* Dup stderr to stdout. */
-  if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
+  if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1) {
     throw SysError("cannot dup stderr into stdout");
+  }
 
   /* Reroute stdin to /dev/null. */
   int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
-  if (fdDevNull == -1)
+  if (fdDevNull == -1) {
     throw SysError(format("cannot open '%1%'") % pathNullDevice);
-  if (dup2(fdDevNull, STDIN_FILENO) == -1)
+  }
+  if (dup2(fdDevNull, STDIN_FILENO) == -1) {
     throw SysError("cannot dup null device into stdin");
+  }
   close(fdDevNull);
 }
 
@@ -444,10 +450,11 @@ void handleDiffHook(uid_t uid, uid_t gid, Path tryA, Path tryB, Path drvPath,
       diffHookOptions.chdir = "/";
 
       auto diffRes = runProgram(diffHookOptions);
-      if (!statusOk(diffRes.first))
+      if (!statusOk(diffRes.first)) {
         throw ExecError(diffRes.first,
                         fmt("diff-hook program '%1%' %2%", diffHook,
                             statusToString(diffRes.first)));
+      }
 
       if (diffRes.second != "") {
         LOG(ERROR) << chomp(diffRes.second);
@@ -503,11 +510,12 @@ UserLock::UserLock() {
 
   /* Get the members of the build-users-group. */
   struct group* gr = getgrnam(settings.buildUsersGroup.get().c_str());
-  if (!gr)
+  if (!gr) {
     throw Error(
         format(
             "the group '%1%' specified in 'build-users-group' does not exist") %
         settings.buildUsersGroup);
+  }
   gid = gr->gr_gid;
 
   /* Copy the result of getgrnam. */
@@ -517,9 +525,10 @@ UserLock::UserLock() {
     users.push_back(*p);
   }
 
-  if (users.empty())
+  if (users.empty()) {
     throw Error(format("the build users group '%1%' has no members") %
                 settings.buildUsersGroup);
+  }
 
   /* Find a user account that isn't currently in use for another
      build. */
@@ -527,9 +536,10 @@ UserLock::UserLock() {
     DLOG(INFO) << "trying user " << i;
 
     struct passwd* pw = getpwnam(i.c_str());
-    if (!pw)
+    if (!pw) {
       throw Error(format("the user '%1%' in the group '%2%' does not exist") %
                   i % settings.buildUsersGroup);
+    }
 
     createDirs(settings.nixStateDir + "/userpool");
 
@@ -538,9 +548,10 @@ UserLock::UserLock() {
 
     {
       auto lockedPaths(lockedPaths_.lock());
-      if (lockedPaths->count(fnUserLock))
+      if (lockedPaths->count(fnUserLock)) {
         /* We already have a lock on this one. */
         continue;
+      }
       lockedPaths->insert(fnUserLock);
     }
 
@@ -557,9 +568,10 @@ UserLock::UserLock() {
         uid = pw->pw_uid;
 
         /* Sanity check... */
-        if (uid == getuid() || uid == geteuid())
+        if (uid == getuid() || uid == geteuid()) {
           throw Error(format("the Nix user should not be a member of '%1%'") %
                       settings.buildUsersGroup);
+        }
 
 #if __linux__
         /* Get the list of supplementary groups of this build user.  This
@@ -568,10 +580,11 @@ UserLock::UserLock() {
         int ngroups = supplementaryGIDs.size();
         int err = getgrouplist(pw->pw_name, pw->pw_gid,
                                supplementaryGIDs.data(), &ngroups);
-        if (err == -1)
+        if (err == -1) {
           throw Error(
               format("failed to get list of supplementary groups for '%1%'") %
               pw->pw_name);
+        }
 
         supplementaryGIDs.resize(ngroups);
 #endif
@@ -673,8 +686,9 @@ HookInstance::HookInstance() {
   sink = FdSink(toHook.writeSide.get());
   std::map<std::string, Config::SettingInfo> settings;
   globalConfig.getSettings(settings);
-  for (auto& setting : settings)
+  for (auto& setting : settings) {
     sink << 1 << setting.first << setting.second.value;
+  }
   sink << 0;
 }
 
@@ -696,8 +710,9 @@ typedef map<std::string, std::string> StringRewrites;
 std::string rewriteStrings(std::string s, const StringRewrites& rewrites) {
   for (auto& i : rewrites) {
     size_t j = 0;
-    while ((j = s.find(i.first, j)) != string::npos)
+    while ((j = s.find(i.first, j)) != string::npos) {
       s.replace(j, i.first.size(), i.second);
+    }
   }
   return s;
 }
@@ -1045,8 +1060,9 @@ void DerivationGoal::killChild() {
       ::kill(-pid, SIGKILL); /* ignore the result */
       buildUser->kill();
       pid.wait();
-    } else
+    } else {
       pid.kill();
+    }
 
     assert(pid == -1);
   }
@@ -1070,12 +1086,14 @@ void DerivationGoal::addWantedOutputs(const StringSet& outputs) {
   if (outputs.empty()) {
     wantedOutputs.clear();
     needRestart = true;
-  } else
-    for (auto& i : outputs)
+  } else {
+    for (auto& i : outputs) {
       if (wantedOutputs.find(i) == wantedOutputs.end()) {
         wantedOutputs.insert(i);
         needRestart = true;
       }
+    }
+  }
 }
 
 void DerivationGoal::getDerivation() {
@@ -1140,15 +1158,18 @@ void DerivationGoal::haveDerivation() {
   /* We are first going to try to create the invalid output paths
      through substitutes.  If that doesn't work, we'll build
      them. */
-  if (settings.useSubstitutes && parsedDrv->substitutesAllowed())
-    for (auto& i : invalidOutputs)
+  if (settings.useSubstitutes && parsedDrv->substitutesAllowed()) {
+    for (auto& i : invalidOutputs) {
       addWaitee(worker.makeSubstitutionGoal(
           i, buildMode == bmRepair ? Repair : NoRepair));
+    }
+  }
 
-  if (waitees.empty()) /* to prevent hang (no wake-up event) */
+  if (waitees.empty()) { /* to prevent hang (no wake-up event) */
     outputsSubstituted();
-  else
+  } else {
     state = &DerivationGoal::outputsSubstituted;
+  }
 }
 
 void DerivationGoal::outputsSubstituted() {
@@ -1189,10 +1210,11 @@ void DerivationGoal::outputsSubstituted() {
     repairClosure();
     return;
   }
-  if (buildMode == bmCheck && nrInvalid > 0)
+  if (buildMode == bmCheck && nrInvalid > 0) {
     throw Error(format("some outputs of '%1%' are not valid, so checking is "
                        "not possible") %
                 drvPath);
+  }
 
   /* Otherwise, at least one of the output paths could not be
      produced using a substitute.  So we have to build instead. */
@@ -1202,26 +1224,30 @@ void DerivationGoal::outputsSubstituted() {
   wantedOutputs = PathSet();
 
   /* The inputs must be built before we can build this goal. */
-  if (useDerivation)
-    for (auto& i : dynamic_cast<Derivation*>(drv.get())->inputDrvs)
+  if (useDerivation) {
+    for (auto& i : dynamic_cast<Derivation*>(drv.get())->inputDrvs) {
       addWaitee(worker.makeDerivationGoal(
           i.first, i.second, buildMode == bmRepair ? bmRepair : bmNormal));
+    }
+  }
 
   for (auto& i : drv->inputSrcs) {
     if (worker.store.isValidPath(i)) {
       continue;
     }
-    if (!settings.useSubstitutes)
+    if (!settings.useSubstitutes) {
       throw Error(format("dependency '%1%' of '%2%' does not exist, and "
                          "substitution is disabled") %
                   i % drvPath);
+    }
     addWaitee(worker.makeSubstitutionGoal(i));
   }
 
-  if (waitees.empty()) /* to prevent hang (no wake-up event) */
+  if (waitees.empty()) { /* to prevent hang (no wake-up event) */
     inputsRealised();
-  else
+  } else {
     state = &DerivationGoal::inputsRealised;
+  }
 }
 
 void DerivationGoal::repairClosure() {
@@ -1252,13 +1278,14 @@ void DerivationGoal::repairClosure() {
     worker.store.computeFSClosure(drvPath, inputClosure);
   }
   std::map<Path, Path> outputsToDrv;
-  for (auto& i : inputClosure)
+  for (auto& i : inputClosure) {
     if (isDerivation(i)) {
       Derivation drv = worker.store.derivationFromPath(i);
       for (auto& j : drv.outputs) {
         outputsToDrv[j.second.path] = i;
       }
     }
+  }
 
   /* Check each path (slow!). */
   PathSet broken;
@@ -1269,10 +1296,11 @@ void DerivationGoal::repairClosure() {
     LOG(ERROR) << "found corrupted or missing path '" << i
                << "' in the output closure of '" << drvPath << "'";
     Path drvPath2 = outputsToDrv[i];
-    if (drvPath2 == "")
+    if (drvPath2 == "") {
       addWaitee(worker.makeSubstitutionGoal(i, Repair));
-    else
+    } else {
       addWaitee(worker.makeDerivationGoal(drvPath2, PathSet(), bmRepair));
+    }
   }
 
   if (waitees.empty()) {
@@ -1285,10 +1313,11 @@ void DerivationGoal::repairClosure() {
 
 void DerivationGoal::closureRepaired() {
   trace("closure repaired");
-  if (nrFailed > 0)
+  if (nrFailed > 0) {
     throw Error(format("some paths in the output closure of derivation '%1%' "
                        "could not be repaired") %
                 drvPath);
+  }
   done(BuildResult::AlreadyValid);
 }
 
@@ -1296,8 +1325,9 @@ void DerivationGoal::inputsRealised() {
   trace("all inputs realised");
 
   if (nrFailed != 0) {
-    if (!useDerivation)
+    if (!useDerivation) {
       throw Error(format("some dependencies of '%1%' are missing") % drvPath);
+    }
     LOG(ERROR) << "cannot build derivation '" << drvPath << "': " << nrFailed
                << " dependencies couldn't be built";
     done(BuildResult::DependencyFailed);
@@ -1321,21 +1351,24 @@ void DerivationGoal::inputsRealised() {
   /* Determine the full set of input paths. */
 
   /* First, the input derivations. */
-  if (useDerivation)
+  if (useDerivation) {
     for (auto& i : dynamic_cast<Derivation*>(drv.get())->inputDrvs) {
       /* Add the relevant output closures of the input derivation
          `i' as input paths.  Only add the closures of output paths
          that are specified as inputs. */
       assert(worker.store.isValidPath(i.first));
       Derivation inDrv = worker.store.derivationFromPath(i.first);
-      for (auto& j : i.second)
-        if (inDrv.outputs.find(j) != inDrv.outputs.end())
+      for (auto& j : i.second) {
+        if (inDrv.outputs.find(j) != inDrv.outputs.end()) {
           worker.store.computeFSClosure(inDrv.outputs[j].path, inputPaths);
-        else
+        } else {
           throw Error(format("derivation '%1%' requires non-existent output "
                              "'%2%' from input derivation '%3%'") %
                       drvPath % j % i.first);
+        }
+      }
     }
+  }
 
   /* Second, the input sources. */
   worker.store.computeFSClosure(drv->inputSrcs, inputPaths);
@@ -1369,8 +1402,9 @@ void DerivationGoal::tryToBuild() {
      goal can start a build, and if not, the main loop will sleep a
      few seconds and then retry this goal. */
   PathSet lockFiles;
-  for (auto& outPath : drv->outputPaths())
+  for (auto& outPath : drv->outputPaths()) {
     lockFiles.insert(worker.store.toRealPath(outPath));
+  }
 
   if (!outputLocks.lockPaths(lockFiles, "", false)) {
     worker.waitForAWhile(shared_from_this());
@@ -1394,10 +1428,11 @@ void DerivationGoal::tryToBuild() {
   }
 
   missingPaths = drv->outputPaths();
-  if (buildMode != bmCheck)
+  if (buildMode != bmCheck) {
     for (auto& i : validPaths) {
       missingPaths.erase(i);
     }
+  }
 
   /* If any of the outputs already exist but are not valid, delete
      them. */
@@ -1494,8 +1529,9 @@ void replaceValidPath(const Path& storePath, const Path tmpPath) {
   if (pathExists(storePath)) {
     rename(storePath.c_str(), oldPath.c_str());
   }
-  if (rename(tmpPath.c_str(), storePath.c_str()) == -1)
+  if (rename(tmpPath.c_str(), storePath.c_str()) == -1) {
     throw SysError(format("moving '%1%' to '%2%'") % tmpPath % storePath);
+  }
   deletePath(oldPath);
 }
 
@@ -1527,8 +1563,9 @@ MakeError(NotDeterministic, BuildError)
   if (hook) {
     hook->builderOut.readSide = -1;
     hook->fromHook.readSide = -1;
-  } else
+  } else {
     builderOut.readSide = -1;
+  }
 
   /* Close the log file. */
   closeLogFile();
@@ -1557,21 +1594,26 @@ MakeError(NotDeterministic, BuildError)
           8ULL * 1024 * 1024;  // FIXME: make configurable
       struct statvfs st;
       if (statvfs(worker.store.realStoreDir.c_str(), &st) == 0 &&
-          (unsigned long long)st.f_bavail * st.f_bsize < required)
+          (unsigned long long)st.f_bavail * st.f_bsize < required) {
         diskFull = true;
+      }
       if (statvfs(tmpDir.c_str(), &st) == 0 &&
-          (unsigned long long)st.f_bavail * st.f_bsize < required)
+          (unsigned long long)st.f_bavail * st.f_bsize < required) {
         diskFull = true;
+      }
 #endif
 
       deleteTmpDir(false);
 
       /* Move paths out of the chroot for easier debugging of
          build failures. */
-      if (useChroot && buildMode == bmNormal)
-        for (auto& i : missingPaths)
-          if (pathExists(chrootRootDir + i))
+      if (useChroot && buildMode == bmNormal) {
+        for (auto& i : missingPaths) {
+          if (pathExists(chrootRootDir + i)) {
             rename((chrootRootDir + i).c_str(), i.c_str());
+          }
+        }
+      }
 
       std::string msg =
           (format("builder for '%1%' %2%") % drvPath % statusToString(status))
@@ -1683,10 +1725,10 @@ MakeError(NotDeterministic, BuildError)
 
     BuildResult::Status st = BuildResult::MiscFailure;
 
-    if (hook && WIFEXITED(status) && WEXITSTATUS(status) == 101)
+    if (hook && WIFEXITED(status) && WEXITSTATUS(status) == 101) {
       st = BuildResult::TimedOut;
 
-    else if (hook && (!WIFEXITED(status) || WEXITSTATUS(status) != 100)) {
+    } else if (hook && (!WIFEXITED(status) || WEXITSTATUS(status) != 100)) {
     }
 
     else {
@@ -1788,8 +1830,9 @@ HookReply DerivationGoal::tryBuildHook() {
 }
 
 void chmod_(const Path& path, mode_t mode) {
-  if (chmod(path.c_str(), mode) == -1)
+  if (chmod(path.c_str(), mode) == -1) {
     throw SysError(format("setting permissions on '%1%'") % path);
+  }
 }
 
 int childEntry(void* arg) {
@@ -1802,18 +1845,20 @@ PathSet DerivationGoal::exportReferences(PathSet storePaths) {
 
   for (auto storePath : storePaths) {
     /* Check that the store path is valid. */
-    if (!worker.store.isInStore(storePath))
+    if (!worker.store.isInStore(storePath)) {
       throw BuildError(
           format("'exportReferencesGraph' contains a non-store path '%1%'") %
           storePath);
+    }
 
     storePath = worker.store.toStorePath(storePath);
 
-    if (!inputPaths.count(storePath))
+    if (!inputPaths.count(storePath)) {
       throw BuildError(
           "cannot export references of path '%s' because it is not in the "
           "input closure of the derivation",
           storePath);
+    }
 
     worker.store.computeFSClosure(storePath, paths);
   }
@@ -1827,8 +1872,9 @@ PathSet DerivationGoal::exportReferences(PathSet storePaths) {
   for (auto& j : paths2) {
     if (isDerivation(j)) {
       Derivation drv = worker.store.derivationFromPath(j);
-      for (auto& k : drv.outputs)
+      for (auto& k : drv.outputs) {
         worker.store.computeFSClosure(k.second.path, paths);
+      }
     }
   }
 
@@ -1859,13 +1905,14 @@ static void preloadNSS() {
 
 void DerivationGoal::startBuilder() {
   /* Right platform? */
-  if (!parsedDrv->canBuildLocally())
+  if (!parsedDrv->canBuildLocally()) {
     throw Error(
         "a '%s' with features {%s} is required to build '%s', but I am a '%s' "
         "with features {%s}",
         drv->platform,
         concatStringsSep(", ", parsedDrv->getRequiredSystemFeatures()), drvPath,
         settings.thisSystem, concatStringsSep(", ", settings.systemFeatures));
+  }
 
   if (drv->isBuiltin()) {
     preloadNSS();
@@ -1880,10 +1927,11 @@ void DerivationGoal::startBuilder() {
   {
     auto noChroot = parsedDrv->getBoolAttr("__noChroot");
     if (settings.sandboxMode == smEnabled) {
-      if (noChroot)
+      if (noChroot) {
         throw Error(format("derivation '%1%' has '__noChroot' set, "
                            "but that's not allowed when 'sandbox' is 'true'") %
                     drvPath);
+      }
 #if __APPLE__
       if (additionalSandboxProfile != "")
         throw Error(
@@ -1892,10 +1940,11 @@ void DerivationGoal::startBuilder() {
             drvPath);
 #endif
       useChroot = true;
-    } else if (settings.sandboxMode == smDisabled)
+    } else if (settings.sandboxMode == smDisabled) {
       useChroot = false;
-    else if (settings.sandboxMode == smRelaxed)
+    } else if (settings.sandboxMode == smRelaxed) {
       useChroot = !fixedOutput && !noChroot;
+    }
   }
 
   if (worker.store.storeDir != worker.store.realStoreDir) {
@@ -1932,8 +1981,9 @@ void DerivationGoal::startBuilder() {
   chownToBuilder(tmpDir);
 
   /* Substitute output placeholders with the actual output paths. */
-  for (auto& output : drv->outputs)
+  for (auto& output : drv->outputs) {
     inputRewrites[hashPlaceholder(output.first)] = output.second.path;
+  }
 
   /* Construct the environment passed to the builder. */
   initEnv();
@@ -1951,9 +2001,10 @@ void DerivationGoal::startBuilder() {
        fields are left empty. */
     string s = get(drv->env, "exportReferencesGraph");
     Strings ss = tokenizeString<Strings>(s);
-    if (ss.size() % 2 != 0)
+    if (ss.size() % 2 != 0) {
       throw BuildError(
           format("odd number of tokens in 'exportReferencesGraph': '%1%'") % s);
+    }
     for (Strings::iterator i = ss.begin(); i != ss.end();) {
       string fileName = *i++;
       checkStoreName(fileName); /* !!! abuse of this function */
@@ -1985,23 +2036,27 @@ void DerivationGoal::startBuilder() {
         i.pop_back();
       }
       size_t p = i.find('=');
-      if (p == string::npos)
+      if (p == string::npos) {
         dirsInChroot[i] = {i, optional};
-      else
+      } else {
         dirsInChroot[string(i, 0, p)] = {string(i, p + 1), optional};
+      }
     }
     dirsInChroot[tmpDirInSandbox] = tmpDir;
 
     /* Add the closure of store paths to the chroot. */
     PathSet closure;
-    for (auto& i : dirsInChroot) try {
-        if (worker.store.isInStore(i.second.source))
+    for (auto& i : dirsInChroot) {
+      try {
+        if (worker.store.isInStore(i.second.source)) {
           worker.store.computeFSClosure(
               worker.store.toStorePath(i.second.source), closure);
+        }
       } catch (InvalidPath& e) {
       } catch (Error& e) {
         throw Error(format("while processing 'sandbox-paths': %s") % e.what());
       }
+    }
     for (auto& i : closure) {
       dirsInChroot[i] = i;
     }
@@ -2027,10 +2082,11 @@ void DerivationGoal::startBuilder() {
           break;
         }
       }
-      if (!found)
+      if (!found) {
         throw Error(format("derivation '%1%' requested impure path '%2%', but "
                            "it was not in allowed-impure-host-deps") %
                     drvPath % i);
+      }
 
       dirsInChroot[i] = i;
     }
@@ -2048,12 +2104,15 @@ void DerivationGoal::startBuilder() {
 
     DLOG(INFO) << "setting up chroot environment in '" << chrootRootDir << "'";
 
-    if (mkdir(chrootRootDir.c_str(), 0750) == -1)
+    if (mkdir(chrootRootDir.c_str(), 0750) == -1) {
       throw SysError(format("cannot create '%1%'") % chrootRootDir);
+    }
 
-    if (buildUser && chown(chrootRootDir.c_str(), 0, buildUser->getGID()) == -1)
+    if (buildUser &&
+        chown(chrootRootDir.c_str(), 0, buildUser->getGID()) == -1) {
       throw SysError(format("cannot change ownership of '%1%'") %
                      chrootRootDir);
+    }
 
     /* Create a writable /tmp in the chroot.  Many builders need
        this.  (Of course they should really respect $TMPDIR
@@ -2082,9 +2141,10 @@ void DerivationGoal::startBuilder() {
                                                 .str());
 
     /* Create /etc/hosts with localhost entry. */
-    if (!fixedOutput)
+    if (!fixedOutput) {
       writeFile(chrootRootDir + "/etc/hosts",
                 "127.0.0.1 localhost\n::1 localhost\n");
+    }
 
     /* Make the closure of the inputs available in the chroot,
        rather than the whole Nix store.  This prevents any access
@@ -2098,18 +2158,20 @@ void DerivationGoal::startBuilder() {
     chmod_(chrootStoreDir, 01775);
 
     if (buildUser &&
-        chown(chrootStoreDir.c_str(), 0, buildUser->getGID()) == -1)
+        chown(chrootStoreDir.c_str(), 0, buildUser->getGID()) == -1) {
       throw SysError(format("cannot change ownership of '%1%'") %
                      chrootStoreDir);
+    }
 
     for (auto& i : inputPaths) {
       Path r = worker.store.toRealPath(i);
       struct stat st;
-      if (lstat(r.c_str(), &st))
+      if (lstat(r.c_str(), &st)) {
         throw SysError(format("getting attributes of path '%1%'") % i);
-      if (S_ISDIR(st.st_mode))
+      }
+      if (S_ISDIR(st.st_mode)) {
         dirsInChroot[i] = r;
-      else {
+      } else {
         Path p = chrootRootDir + i;
         DLOG(INFO) << "linking '" << p << "' to '" << r << "'";
         if (link(r.c_str(), p.c_str()) == -1) {
@@ -2117,8 +2179,9 @@ void DerivationGoal::startBuilder() {
              link count on a file (e.g. 32000 of ext3),
              which is quite possible after a `nix-store
              --optimise'. */
-          if (errno != EMLINK)
+          if (errno != EMLINK) {
             throw SysError(format("linking '%1%' to '%2%'") % p % i);
+          }
           StringSink sink;
           dumpPath(r, sink);
           StringSource source(*sink.s);
@@ -2145,8 +2208,9 @@ void DerivationGoal::startBuilder() {
   }
 
   if (needsHashRewrite()) {
-    if (pathExists(homeDir))
+    if (pathExists(homeDir)) {
       throw Error(format("directory '%1%' exists; please remove it") % homeDir);
+    }
 
     /* We're not doing a chroot build, but we have some valid
        output paths.  Since we can't just overwrite or delete
@@ -2157,19 +2221,22 @@ void DerivationGoal::startBuilder() {
        corresponding to the valid outputs, and rewrite the
        contents of the new outputs to replace the dummy strings
        with the actual hashes. */
-    if (validPaths.size() > 0)
+    if (validPaths.size() > 0) {
       for (auto& i : validPaths) {
         addHashRewrite(i);
       }
+    }
 
     /* If we're repairing, then we don't want to delete the
        corrupt outputs in advance.  So rewrite them as well. */
-    if (buildMode == bmRepair)
-      for (auto& i : missingPaths)
+    if (buildMode == bmRepair) {
+      for (auto& i : missingPaths) {
         if (worker.store.isValidPath(i) && pathExists(i)) {
           addHashRewrite(i);
           redirectedBadOutputs.insert(i);
         }
+      }
+    }
   }
 
   if (useChroot && settings.preBuildHook != "" &&
@@ -2196,10 +2263,11 @@ void DerivationGoal::startBuilder() {
           state = stBegin;
         } else {
           auto p = line.find('=');
-          if (p == string::npos)
+          if (p == string::npos) {
             dirsInChroot[line] = line;
-          else
+          } else {
             dirsInChroot[string(line, 0, p)] = string(line, p + 1);
+          }
         }
       }
     }
@@ -2222,14 +2290,17 @@ void DerivationGoal::startBuilder() {
   std::string slaveName(ptsname(builderOut.readSide.get()));
 
   if (buildUser) {
-    if (chmod(slaveName.c_str(), 0600))
+    if (chmod(slaveName.c_str(), 0600)) {
       throw SysError("changing mode of pseudoterminal slave");
+    }
 
-    if (chown(slaveName.c_str(), buildUser->getUID(), 0))
+    if (chown(slaveName.c_str(), buildUser->getUID(), 0)) {
       throw SysError("changing owner of pseudoterminal slave");
+    }
   } else {
-    if (grantpt(builderOut.readSide.get()))
+    if (grantpt(builderOut.readSide.get())) {
       throw SysError("granting access to pseudoterminal slave");
+    }
   }
 
 #if 0
@@ -2239,8 +2310,9 @@ void DerivationGoal::startBuilder() {
         dirsInChroot[slaveName] = {slaveName, false};
 #endif
 
-  if (unlockpt(builderOut.readSide.get()))
+  if (unlockpt(builderOut.readSide.get())) {
     throw SysError("unlocking pseudoterminal");
+  }
 
   builderOut.writeSide = open(slaveName.c_str(), O_RDWR | O_NOCTTY);
   if (!builderOut.writeSide) {
@@ -2249,13 +2321,15 @@ void DerivationGoal::startBuilder() {
 
   // Put the pt into raw mode to prevent \n -> \r\n translation.
   struct termios term;
-  if (tcgetattr(builderOut.writeSide.get(), &term))
+  if (tcgetattr(builderOut.writeSide.get(), &term)) {
     throw SysError("getting pseudoterminal attributes");
+  }
 
   cfmakeraw(&term);
 
-  if (tcsetattr(builderOut.writeSide.get(), TCSANOW, &term))
+  if (tcsetattr(builderOut.writeSide.get(), TCSANOW, &term)) {
     throw SysError("putting pseudoterminal into raw mode");
+  }
 
   result.startTime = time(0);
 
@@ -2316,8 +2390,9 @@ void DerivationGoal::startBuilder() {
              not seem to be a workaround for this. (But who can tell
              from reading user_namespaces(7)?)
              See also https://lwn.net/Articles/621612/. */
-          if (getuid() == 0 && setgroups(0, 0) == -1)
+          if (getuid() == 0 && setgroups(0, 0) == -1) {
             throw SysError("setgroups failed");
+          }
 
           size_t stackSize = 1 * 1024 * 1024;
           char* stack =
@@ -2352,8 +2427,9 @@ void DerivationGoal::startBuilder() {
              parent. This is only done when sandbox-fallback is set
              to true (the default). */
           if (child == -1 && (errno == EPERM || errno == EINVAL) &&
-              settings.sandboxFallback)
+              settings.sandboxFallback) {
             _exit(1);
+          }
           if (child == -1) {
             throw SysError("cloning builder process");
           }
@@ -2368,8 +2444,9 @@ void DerivationGoal::startBuilder() {
       useChroot = false;
       initTmpDir();
       goto fallback;
-    } else if (res != 0)
+    } else if (res != 0) {
       throw Error("unable to start build process");
+    }
 
     userNamespaceSync.readSide = -1;
 
@@ -2518,8 +2595,9 @@ void DerivationGoal::initEnv() {
      already know the cryptographic hash of the output). */
   if (fixedOutput) {
     for (auto& i :
-         parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings()))
+         parsedDrv->getStringsAttr("impureEnvVars").value_or(Strings())) {
       env[i] = getEnv(i);
+    }
   }
 
   /* Currently structured log messages piggyback on stderr, but we
@@ -2543,8 +2621,9 @@ void DerivationGoal::writeStructuredAttrs() {
 
   /* Add an "outputs" object containing the output paths. */
   nlohmann::json outputs;
-  for (auto& i : drv->outputs)
+  for (auto& i : drv->outputs) {
     outputs[i.first] = rewriteStrings(i.second.path, inputRewrites);
+  }
   json["outputs"] = outputs;
 
   /* Handle exportReferencesGraph. */
@@ -2592,8 +2671,9 @@ void DerivationGoal::writeStructuredAttrs() {
       return std::string("''");
     }
 
-    if (value.is_boolean())
+    if (value.is_boolean()) {
       return value.get<bool>() ? std::string("1") : std::string("");
+    }
 
     return {};
   };
@@ -2608,10 +2688,10 @@ void DerivationGoal::writeStructuredAttrs() {
     auto& value = i.value();
 
     auto s = handleSimpleType(value);
-    if (s)
+    if (s) {
       jsonSh += fmt("declare %s=%s\n", i.key(), *s);
 
-    else if (value.is_array()) {
+    } else if (value.is_array()) {
       std::string s2;
       bool good = true;
 
@@ -2657,8 +2737,9 @@ void DerivationGoal::chownToBuilder(const Path& path) {
   if (!buildUser) {
     return;
   }
-  if (chown(path.c_str(), buildUser->getUID(), buildUser->getGID()) == -1)
+  if (chown(path.c_str(), buildUser->getUID(), buildUser->getGID()) == -1) {
     throw SysError(format("cannot change ownership of '%1%'") % path);
+  }
 }
 
 void setupSeccomp() {
@@ -2669,18 +2750,21 @@ void setupSeccomp() {
 #if HAVE_SECCOMP
   scmp_filter_ctx ctx;
 
-  if (!(ctx = seccomp_init(SCMP_ACT_ALLOW)))
+  if (!(ctx = seccomp_init(SCMP_ACT_ALLOW))) {
     throw SysError("unable to initialize seccomp mode 2");
+  }
 
   Finally cleanup([&]() { seccomp_release(ctx); });
 
   if (nativeSystem == "x86_64-linux" &&
-      seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0)
+      seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0) {
     throw SysError("unable to add 32-bit seccomp architecture");
+  }
 
   if (nativeSystem == "x86_64-linux" &&
-      seccomp_arch_add(ctx, SCMP_ARCH_X32) != 0)
+      seccomp_arch_add(ctx, SCMP_ARCH_X32) != 0) {
     throw SysError("unable to add X32 seccomp architecture");
+  }
 
   if (nativeSystem == "aarch64-linux" &&
       seccomp_arch_add(ctx, SCMP_ARCH_ARM) != 0) {
@@ -2692,18 +2776,21 @@ void setupSeccomp() {
   for (int perm : {S_ISUID, S_ISGID}) {
     if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(chmod), 1,
                          SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t)perm,
-                                 (scmp_datum_t)perm)) != 0)
+                                 (scmp_datum_t)perm)) != 0) {
       throw SysError("unable to add seccomp rule");
+    }
 
     if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmod), 1,
                          SCMP_A1(SCMP_CMP_MASKED_EQ, (scmp_datum_t)perm,
-                                 (scmp_datum_t)perm)) != 0)
+                                 (scmp_datum_t)perm)) != 0) {
       throw SysError("unable to add seccomp rule");
+    }
 
     if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EPERM), SCMP_SYS(fchmodat), 1,
                          SCMP_A2(SCMP_CMP_MASKED_EQ, (scmp_datum_t)perm,
-                                 (scmp_datum_t)perm)) != 0)
+                                 (scmp_datum_t)perm)) != 0) {
       throw SysError("unable to add seccomp rule");
+    }
   }
 
   /* Prevent builders from creating EAs or ACLs. Not all filesystems
@@ -2714,15 +2801,18 @@ void setupSeccomp() {
       seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(lsetxattr), 0) !=
           0 ||
       seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOTSUP), SCMP_SYS(fsetxattr), 0) !=
-          0)
+          0) {
     throw SysError("unable to add seccomp rule");
+  }
 
   if (seccomp_attr_set(ctx, SCMP_FLTATR_CTL_NNP,
-                       settings.allowNewPrivileges ? 0 : 1) != 0)
+                       settings.allowNewPrivileges ? 0 : 1) != 0) {
     throw SysError("unable to set 'no new privileges' seccomp attribute");
+  }
 
-  if (seccomp_load(ctx) != 0)
+  if (seccomp_load(ctx) != 0) {
     throw SysError("unable to load seccomp BPF program");
+  }
 #else
   throw Error(
       "seccomp is not supported on this platform; "
@@ -2754,8 +2844,9 @@ void DerivationGoal::runChild() {
        (which may run under a different uid and/or in a sandbox). */
     std::string netrcData;
     try {
-      if (drv->isBuiltin() && drv->builder == "builtin:fetchurl")
+      if (drv->isBuiltin() && drv->builder == "builtin:fetchurl") {
         netrcData = readFile(settings.netrcFile);
+      }
     } catch (SysError&) {
     }
 
@@ -2763,8 +2854,9 @@ void DerivationGoal::runChild() {
     if (useChroot) {
       userNamespaceSync.writeSide = -1;
 
-      if (drainFD(userNamespaceSync.readSide.get()) != "1")
+      if (drainFD(userNamespaceSync.readSide.get()) != "1") {
         throw Error("user namespace initialisation failed");
+      }
 
       userNamespaceSync.readSide = -1;
 
@@ -2778,17 +2870,20 @@ void DerivationGoal::runChild() {
         struct ifreq ifr;
         strcpy(ifr.ifr_name, "lo");
         ifr.ifr_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING;
-        if (ioctl(fd.get(), SIOCSIFFLAGS, &ifr) == -1)
+        if (ioctl(fd.get(), SIOCSIFFLAGS, &ifr) == -1) {
           throw SysError("cannot set loopback interface flags");
+        }
       }
 
       /* Set the hostname etc. to fixed values. */
       char hostname[] = "localhost";
-      if (sethostname(hostname, sizeof(hostname)) == -1)
+      if (sethostname(hostname, sizeof(hostname)) == -1) {
         throw SysError("cannot set host name");
+      }
       char domainname[] = "(none)";  // kernel default
-      if (setdomainname(domainname, sizeof(domainname)) == -1)
+      if (setdomainname(domainname, sizeof(domainname)) == -1) {
         throw SysError("cannot set domain name");
+      }
 
       /* Make all filesystems private.  This is necessary
          because subtrees may have been mounted as "shared"
@@ -2805,8 +2900,9 @@ void DerivationGoal::runChild() {
       /* Bind-mount chroot directory to itself, to treat it as a
          different filesystem from /, as needed for pivot_root. */
       if (mount(chrootRootDir.c_str(), chrootRootDir.c_str(), 0, MS_BIND, 0) ==
-          -1)
+          -1) {
         throw SysError(format("unable to bind mount '%1%'") % chrootRootDir);
+      }
 
       /* Set up a nearly empty /dev, unless the user asked to
          bind-mount the host /dev. */
@@ -2816,8 +2912,9 @@ void DerivationGoal::runChild() {
         createDirs(chrootRootDir + "/dev/pts");
         ss.push_back("/dev/full");
         if (settings.systemFeatures.get().count("kvm") &&
-            pathExists("/dev/kvm"))
+            pathExists("/dev/kvm")) {
           ss.push_back("/dev/kvm");
+        }
         ss.push_back("/dev/null");
         ss.push_back("/dev/random");
         ss.push_back("/dev/tty");
@@ -2844,8 +2941,9 @@ void DerivationGoal::runChild() {
 
         ss.push_back("/etc/services");
         ss.push_back("/etc/hosts");
-        if (pathExists("/var/run/nscd/socket"))
+        if (pathExists("/var/run/nscd/socket")) {
           ss.push_back("/var/run/nscd/socket");
+        }
       }
 
       for (auto& i : ss) {
@@ -2860,21 +2958,23 @@ void DerivationGoal::runChild() {
         DLOG(INFO) << "bind mounting '" << source << "' to '" << target << "'";
         struct stat st;
         if (stat(source.c_str(), &st) == -1) {
-          if (optional && errno == ENOENT)
+          if (optional && errno == ENOENT) {
             return;
-          else
+          } else {
             throw SysError("getting attributes of path '%1%'", source);
+          }
         }
-        if (S_ISDIR(st.st_mode))
+        if (S_ISDIR(st.st_mode)) {
           createDirs(target);
-        else {
+        } else {
           createDirs(dirOf(target));
           writeFile(target, "");
         }
         if (mount(source.c_str(), target.c_str(), "", MS_BIND | MS_REC, 0) ==
-            -1)
+            -1) {
           throw SysError("bind mount from '%1%' to '%2%' failed", source,
                          target);
+        }
       };
 
       for (auto& i : dirsInChroot) {
@@ -2886,15 +2986,18 @@ void DerivationGoal::runChild() {
 
       /* Bind a new instance of procfs on /proc. */
       createDirs(chrootRootDir + "/proc");
-      if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) == -1)
+      if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) ==
+          -1) {
         throw SysError("mounting /proc");
+      }
 
       /* Mount a new tmpfs on /dev/shm to ensure that whatever
          the builder puts in /dev/shm is cleaned up automatically. */
       if (pathExists("/dev/shm") &&
           mount("none", (chrootRootDir + "/dev/shm").c_str(), "tmpfs", 0,
-                fmt("size=%s", settings.sandboxShmSize).c_str()) == -1)
+                fmt("size=%s", settings.sandboxShmSize).c_str()) == -1) {
         throw SysError("mounting /dev/shm");
+      }
 
       /* Mount a new devpts on /dev/pts.  Note that this
          requires the kernel to be compiled with
@@ -2920,26 +3023,32 @@ void DerivationGoal::runChild() {
       }
 
       /* Do the chroot(). */
-      if (chdir(chrootRootDir.c_str()) == -1)
+      if (chdir(chrootRootDir.c_str()) == -1) {
         throw SysError(format("cannot change directory to '%1%'") %
                        chrootRootDir);
+      }
 
-      if (mkdir("real-root", 0) == -1)
+      if (mkdir("real-root", 0) == -1) {
         throw SysError("cannot create real-root directory");
+      }
 
-      if (pivot_root(".", "real-root") == -1)
+      if (pivot_root(".", "real-root") == -1) {
         throw SysError(format("cannot pivot old root directory onto '%1%'") %
                        (chrootRootDir + "/real-root"));
+      }
 
-      if (chroot(".") == -1)
+      if (chroot(".") == -1) {
         throw SysError(format("cannot change root directory to '%1%'") %
                        chrootRootDir);
+      }
 
-      if (umount2("real-root", MNT_DETACH) == -1)
+      if (umount2("real-root", MNT_DETACH) == -1) {
         throw SysError("cannot unmount real root filesystem");
+      }
 
-      if (rmdir("real-root") == -1)
+      if (rmdir("real-root") == -1) {
         throw SysError("cannot remove real-root directory");
+      }
 
       /* Switch to the sandbox uid/gid in the user namespace,
          which corresponds to the build user or calling user in
@@ -2955,8 +3064,9 @@ void DerivationGoal::runChild() {
     }
 #endif
 
-    if (chdir(tmpDirInSandbox.c_str()) == -1)
+    if (chdir(tmpDirInSandbox.c_str()) == -1) {
       throw SysError(format("changing into '%1%'") % tmpDir);
+    }
 
     /* Close all other file descriptors. */
     closeMostFDs({STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO});
@@ -2970,8 +3080,9 @@ void DerivationGoal::runChild() {
         (settings.thisSystem == "x86_64-linux" ||
          (!strcmp(utsbuf.sysname, "Linux") &&
           !strcmp(utsbuf.machine, "x86_64")))) {
-      if (personality(PER_LINUX32) == -1)
+      if (personality(PER_LINUX32) == -1) {
         throw SysError("cannot set i686-linux personality");
+      }
     }
 
     /* Impersonate a Linux 2.6 machine to get some determinism in
@@ -3000,9 +3111,10 @@ void DerivationGoal::runChild() {
 
     /* Fill in the environment. */
     Strings envStrs;
-    for (auto& i : env)
+    for (auto& i : env) {
       envStrs.push_back(
           rewriteStrings(i.first + "=" + i.second, inputRewrites));
+    }
 
     /* If we are running in `build-users' mode, then switch to the
        user we allocated above.  Make sure that we drop all root
@@ -3015,16 +3127,19 @@ void DerivationGoal::runChild() {
          admins to specify groups such as "kvm".  */
       if (!buildUser->getSupplementaryGIDs().empty() &&
           setgroups(buildUser->getSupplementaryGIDs().size(),
-                    buildUser->getSupplementaryGIDs().data()) == -1)
+                    buildUser->getSupplementaryGIDs().data()) == -1) {
         throw SysError("cannot set supplementary groups of build user");
+      }
 
       if (setgid(buildUser->getGID()) == -1 ||
-          getgid() != buildUser->getGID() || getegid() != buildUser->getGID())
+          getgid() != buildUser->getGID() || getegid() != buildUser->getGID()) {
         throw SysError("setgid failed");
+      }
 
       if (setuid(buildUser->getUID()) == -1 ||
-          getuid() != buildUser->getUID() || geteuid() != buildUser->getUID())
+          getuid() != buildUser->getUID() || geteuid() != buildUser->getUID()) {
         throw SysError("setuid failed");
+      }
     }
 
     /* Fill in the arguments. */
@@ -3190,16 +3305,18 @@ void DerivationGoal::runChild() {
     if (drv->isBuiltin()) {
       try {
         BasicDerivation drv2(*drv);
-        for (auto& e : drv2.env)
+        for (auto& e : drv2.env) {
           e.second = rewriteStrings(e.second, inputRewrites);
+        }
 
-        if (drv->builder == "builtin:fetchurl")
+        if (drv->builder == "builtin:fetchurl") {
           builtinFetchurl(drv2, netrcData);
-        else if (drv->builder == "builtin:buildenv")
+        } else if (drv->builder == "builtin:buildenv") {
           builtinBuildenv(drv2);
-        else
+        } else {
           throw Error(format("unsupported builtin function '%1%'") %
                       string(drv->builder, 8));
+        }
         _exit(0);
       } catch (std::exception& e) {
         writeFull(STDERR_FILENO, "error: " + string(e.what()) + "\n");
@@ -3226,14 +3343,15 @@ PathSet parseReferenceSpecifiers(Store& store, const BasicDerivation& drv,
                                  const Strings& paths) {
   PathSet result;
   for (auto& i : paths) {
-    if (store.isStorePath(i))
+    if (store.isStorePath(i)) {
       result.insert(i);
-    else if (drv.outputs.find(i) != drv.outputs.end())
+    } else if (drv.outputs.find(i) != drv.outputs.end()) {
       result.insert(drv.outputs.find(i)->second.path);
-    else
+    } else {
       throw BuildError(
           format("derivation contains an illegal reference specifier '%1%'") %
           i);
+    }
   }
   return result;
 }
@@ -3244,10 +3362,11 @@ void DerivationGoal::registerOutputs() {
      to do anything here. */
   if (hook) {
     bool allValid = true;
-    for (auto& i : drv->outputs)
+    for (auto& i : drv->outputs) {
       if (!worker.store.isValidPath(i.second.path)) {
         allValid = false;
       }
+    }
     if (allValid) {
       return;
     }
@@ -3281,14 +3400,15 @@ void DerivationGoal::registerOutputs() {
       actualPath = chrootRootDir + path;
       if (pathExists(actualPath)) {
         /* Move output paths from the chroot to the Nix store. */
-        if (buildMode == bmRepair)
+        if (buildMode == bmRepair) {
           replaceValidPath(path, actualPath);
-        else if (buildMode != bmCheck &&
-                 rename(actualPath.c_str(),
-                        worker.store.toRealPath(path).c_str()) == -1)
+        } else if (buildMode != bmCheck &&
+                   rename(actualPath.c_str(),
+                          worker.store.toRealPath(path).c_str()) == -1) {
           throw SysError(format("moving build output '%1%' from the sandbox to "
                                 "the Nix store") %
                          path);
+        }
       }
       if (buildMode != bmCheck) {
         actualPath = worker.store.toRealPath(path);
@@ -3299,8 +3419,9 @@ void DerivationGoal::registerOutputs() {
       Path redirected = redirectedOutputs[path];
       if (buildMode == bmRepair &&
           redirectedBadOutputs.find(path) != redirectedBadOutputs.end() &&
-          pathExists(redirected))
+          pathExists(redirected)) {
         replaceValidPath(path, redirected);
+      }
       if (buildMode == bmCheck && redirected != "") {
         actualPath = redirected;
       }
@@ -3308,10 +3429,11 @@ void DerivationGoal::registerOutputs() {
 
     struct stat st;
     if (lstat(actualPath.c_str(), &st) == -1) {
-      if (errno == ENOENT)
+      if (errno == ENOENT) {
         throw BuildError(
             format("builder for '%1%' failed to produce output path '%2%'") %
             drvPath % path);
+      }
       throw SysError(format("getting attributes of path '%1%'") % actualPath);
     }
 
@@ -3321,10 +3443,11 @@ void DerivationGoal::registerOutputs() {
        build.  Also, the output should be owned by the build
        user. */
     if ((!S_ISLNK(st.st_mode) && (st.st_mode & (S_IWGRP | S_IWOTH))) ||
-        (buildUser && st.st_uid != buildUser->getUID()))
+        (buildUser && st.st_uid != buildUser->getUID())) {
       throw BuildError(format("suspicious ownership or permission on '%1%'; "
                               "rejecting this build output") %
                        path);
+    }
 #endif
 
     /* Apply hash rewriting if necessary. */
@@ -3360,11 +3483,12 @@ void DerivationGoal::registerOutputs() {
       if (!recursive) {
         /* The output path should be a regular file without
            execute permission. */
-        if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0)
+        if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0) {
           throw BuildError(
               format(
                   "output path '%1%' should be a non-executable regular file") %
               path);
+        }
       }
 
       /* Check the hash. In hash mode, move the path produced by
@@ -3386,20 +3510,23 @@ void DerivationGoal::registerOutputs() {
 
         Path actualDest = worker.store.toRealPath(dest);
 
-        if (worker.store.isValidPath(dest))
+        if (worker.store.isValidPath(dest)) {
           std::rethrow_exception(delayedException);
+        }
 
         if (actualPath != actualDest) {
           PathLocks outputLocks({actualDest});
           deletePath(actualDest);
-          if (rename(actualPath.c_str(), actualDest.c_str()) == -1)
+          if (rename(actualPath.c_str(), actualDest.c_str()) == -1) {
             throw SysError(format("moving '%1%' to '%2%'") % actualPath % dest);
+          }
         }
 
         path = dest;
         actualPath = actualDest;
-      } else
+      } else {
         assert(path == dest);
+      }
 
       info.ca = makeFixedOutputCA(recursive, h2);
     }
@@ -3428,9 +3555,10 @@ void DerivationGoal::registerOutputs() {
         if (settings.runDiffHook || settings.keepFailed) {
           Path dst = worker.store.toRealPath(path + checkSuffix);
           deletePath(dst);
-          if (rename(actualPath.c_str(), dst.c_str()))
+          if (rename(actualPath.c_str(), dst.c_str())) {
             throw SysError(format("renaming '%1%' to '%2%'") % actualPath %
                            dst);
+          }
 
           handleDiffHook(buildUser ? buildUser->getUID() : getuid(),
                          buildUser ? buildUser->getGID() : getgid(), path, dst,
@@ -3440,10 +3568,11 @@ void DerivationGoal::registerOutputs() {
               format("derivation '%1%' may not be deterministic: output '%2%' "
                      "differs from '%3%'") %
               drvPath % path % dst);
-        } else
+        } else {
           throw NotDeterministic(format("derivation '%1%' may not be "
                                         "deterministic: output '%2%' differs") %
                                  drvPath % path);
+        }
       }
 
       /* Since we verified the build, it's now ultimately
@@ -3461,10 +3590,11 @@ void DerivationGoal::registerOutputs() {
        paths. */
     for (auto& i : inputPaths) {
       PathSet::iterator j = references.find(i);
-      if (j == references.end())
+      if (j == references.end()) {
         DLOG(INFO) << "unreferenced input: '" << i << "'";
-      else
+      } else {
         DLOG(INFO) << "referenced input: '" << i << "'";
+      }
     }
 
     if (curRound == nrRounds) {
@@ -3500,7 +3630,7 @@ void DerivationGoal::registerOutputs() {
   if (curRound > 1 && prevInfos != infos) {
     assert(prevInfos.size() == infos.size());
     for (auto i = prevInfos.begin(), j = infos.begin(); i != prevInfos.end();
-         ++i, ++j)
+         ++i, ++j) {
       if (!(*i == *j)) {
         result.isNonDeterministic = true;
         Path prev = i->second.path + checkSuffix;
@@ -3524,6 +3654,7 @@ void DerivationGoal::registerOutputs() {
         LOG(ERROR) << msg;
         curRound = nrRounds;  // we know enough, bail out early
       }
+    }
   }
 
   /* If this is the first round of several, then move the output out
@@ -3534,8 +3665,9 @@ void DerivationGoal::registerOutputs() {
       Path prev = i.second.path + checkSuffix;
       deletePath(prev);
       Path dst = i.second.path + checkSuffix;
-      if (rename(i.second.path.c_str(), dst.c_str()))
+      if (rename(i.second.path.c_str(), dst.c_str())) {
         throw SysError(format("renaming '%1%' to '%2%'") % i.second.path % dst);
+      }
     }
   }
 
@@ -3574,8 +3706,9 @@ void DerivationGoal::registerOutputs() {
 void DerivationGoal::checkOutputs(
     const std::map<Path, ValidPathInfo>& outputs) {
   std::map<Path, const ValidPathInfo&> outputsByPath;
-  for (auto& output : outputs)
+  for (auto& output : outputs) {
     outputsByPath.emplace(output.second.path, output.second);
+  }
 
   for (auto& output : outputs) {
     auto& outputName = output.first;
@@ -3623,18 +3756,20 @@ void DerivationGoal::checkOutputs(
     };
 
     auto applyChecks = [&](const Checks& checks) {
-      if (checks.maxSize && info.narSize > *checks.maxSize)
+      if (checks.maxSize && info.narSize > *checks.maxSize) {
         throw BuildError(
             "path '%s' is too large at %d bytes; limit is %d bytes", info.path,
             info.narSize, *checks.maxSize);
+      }
 
       if (checks.maxClosureSize) {
         uint64_t closureSize = getClosure(info.path).second;
-        if (closureSize > *checks.maxClosureSize)
+        if (closureSize > *checks.maxClosureSize) {
           throw BuildError(
               "closure of path '%s' is too large at %d bytes; limit is %d "
               "bytes",
               info.path, closureSize, *checks.maxClosureSize);
+        }
       }
 
       auto checkRefs = [&](const std::optional<Strings>& value, bool allowed,
@@ -3654,7 +3789,7 @@ void DerivationGoal::checkOutputs(
 
         PathSet badPaths;
 
-        for (auto& i : used)
+        for (auto& i : used) {
           if (allowed) {
             if (!spec.count(i)) {
               badPaths.insert(i);
@@ -3664,6 +3799,7 @@ void DerivationGoal::checkOutputs(
               badPaths.insert(i);
             }
           }
+        }
 
         if (!badPaths.empty()) {
           string badPathsStr;
@@ -3692,23 +3828,26 @@ void DerivationGoal::checkOutputs(
           Checks checks;
 
           auto maxSize = output->find("maxSize");
-          if (maxSize != output->end())
+          if (maxSize != output->end()) {
             checks.maxSize = maxSize->get<uint64_t>();
+          }
 
           auto maxClosureSize = output->find("maxClosureSize");
-          if (maxClosureSize != output->end())
+          if (maxClosureSize != output->end()) {
             checks.maxClosureSize = maxClosureSize->get<uint64_t>();
+          }
 
           auto get = [&](const std::string& name) -> std::optional<Strings> {
             auto i = output->find(name);
             if (i != output->end()) {
               Strings res;
               for (auto j = i->begin(); j != i->end(); ++j) {
-                if (!j->is_string())
+                if (!j->is_string()) {
                   throw Error(
                       "attribute '%s' of derivation '%s' must be a list of "
                       "strings",
                       name, drvPath);
+                }
                 res.push_back(j->get<std::string>());
               }
               checks.disallowedRequisites = res;
@@ -3759,16 +3898,18 @@ Path DerivationGoal::openLogFile() {
 
   fdLogFile =
       open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0666);
-  if (!fdLogFile)
+  if (!fdLogFile) {
     throw SysError(format("creating log file '%1%'") % logFileName);
+  }
 
   logFileSink = std::make_shared<FdSink>(fdLogFile.get());
 
-  if (settings.compressLog)
+  if (settings.compressLog) {
     logSink = std::shared_ptr<CompressionSink>(
         makeCompressionSink("bzip2", *logFileSink));
-  else
+  } else {
     logSink = logFileSink;
+  }
 
   return logFileName;
 }
@@ -3792,8 +3933,9 @@ void DerivationGoal::deleteTmpDir(bool force) {
     if (settings.keepFailed && !force && !drv->isBuiltin()) {
       LOG(INFO) << "note: keeping build directory '" << tmpDir << "'";
       chmod(tmpDir.c_str(), 0755);
-    } else
+    } else {
       deletePath(tmpDir);
+    }
     tmpDir = "";
   }
 }
@@ -3811,27 +3953,32 @@ void DerivationGoal::handleChildOutput(int fd, const string& data) {
       return;
     }
 
-    for (auto c : data)
+    for (auto c : data) {
       if (c == '\r') {
         currentLogLinePos = 0;
       } else if (c == '\n') {
         flushLine();
       } else {
-        if (currentLogLinePos >= currentLogLine.size())
+        if (currentLogLinePos >= currentLogLine.size()) {
           currentLogLine.resize(currentLogLinePos + 1);
+        }
         currentLogLine[currentLogLinePos++] = c;
       }
+    }
 
-    if (logSink) (*logSink)(data);
+    if (logSink) {
+      (*logSink)(data);
+    }
   }
 
   if (hook && fd == hook->fromHook.readSide.get()) {
-    for (auto c : data)
+    for (auto c : data) {
       if (c == '\n') {
         currentHookLine.clear();
       } else {
         currentHookLine += c;
       }
+    }
   }
 }
 
@@ -3843,9 +3990,10 @@ void DerivationGoal::handleEOF(int fd) {
 }
 
 void DerivationGoal::flushLine() {
-  if (settings.verboseBuild && (settings.printRepeatedBuilds || curRound == 1))
+  if (settings.verboseBuild &&
+      (settings.printRepeatedBuilds || curRound == 1)) {
     LOG(INFO) << currentLogLine;
-  else {
+  } else {
     logTail.push_back(currentLogLine);
     if (logTail.size() > settings.logLines) {
       logTail.pop_front();
@@ -3893,8 +4041,9 @@ void DerivationGoal::done(BuildResult::Status status, const string& msg) {
   if (result.status == BuildResult::TimedOut) {
     worker.timedOut = true;
   }
-  if (result.status == BuildResult::PermanentFailure)
+  if (result.status == BuildResult::PermanentFailure) {
     worker.permanentFailure = true;
+  }
 
   mcExpectedBuilds.reset();
   mcRunningBuilds.reset();
@@ -4021,11 +4170,12 @@ void SubstitutionGoal::init() {
     return;
   }
 
-  if (settings.readOnlyMode)
+  if (settings.readOnlyMode) {
     throw Error(
         format(
             "cannot substitute path '%1%' - no write access to the Nix store") %
         storePath);
+  }
 
   subs = settings.useSubstitutes ? getDefaultSubstituters()
                                  : std::list<ref<Store>>();
@@ -4110,14 +4260,17 @@ void SubstitutionGoal::tryNext() {
 
   /* To maintain the closure invariant, we first have to realise the
      paths referenced by this one. */
-  for (auto& i : info->references)
-    if (i != storePath) /* ignore self-references */
+  for (auto& i : info->references) {
+    if (i != storePath) { /* ignore self-references */
       addWaitee(worker.makeSubstitutionGoal(i));
+    }
+  }
 
-  if (waitees.empty()) /* to prevent hang (no wake-up event) */
+  if (waitees.empty()) { /* to prevent hang (no wake-up event) */
     referencesValid();
-  else
+  } else {
     state = &SubstitutionGoal::referencesValid;
+  }
 }
 
 void SubstitutionGoal::referencesValid() {
@@ -4131,9 +4284,11 @@ void SubstitutionGoal::referencesValid() {
     return;
   }
 
-  for (auto& i : info->references)
-    if (i != storePath) /* ignore self-references */
+  for (auto& i : info->references) {
+    if (i != storePath) { /* ignore self-references */
       assert(worker.store.isValidPath(i));
+    }
+  }
 
   state = &SubstitutionGoal::tryToRun;
   worker.wakeUp(shared_from_this());
@@ -4304,14 +4459,16 @@ GoalPtr Worker::makeSubstitutionGoal(const Path& path, RepairFlag repair) {
 
 static void removeGoal(GoalPtr goal, WeakGoalMap& goalMap) {
   /* !!! inefficient */
-  for (WeakGoalMap::iterator i = goalMap.begin(); i != goalMap.end();)
+  for (WeakGoalMap::iterator i = goalMap.begin(); i != goalMap.end();) {
     if (i->second.lock() == goal) {
       WeakGoalMap::iterator j = i;
       ++j;
       goalMap.erase(i);
       i = j;
-    } else
+    } else {
       ++i;
+    }
+  }
 }
 
 void Worker::removeGoal(GoalPtr goal) {
@@ -4321,8 +4478,9 @@ void Worker::removeGoal(GoalPtr goal) {
     topGoals.erase(goal);
     /* If a top-level goal failed, then kill all other goals
        (unless keepGoing was set). */
-    if (goal->getExitCode() == Goal::ecFailed && !settings.keepGoing)
+    if (goal->getExitCode() == Goal::ecFailed && !settings.keepGoing) {
       topGoals.clear();
+    }
   }
 
   /* Wake up goals waiting for any goal to finish. */
@@ -4388,10 +4546,11 @@ void Worker::childTerminated(Goal* goal, bool wakeSleepers) {
 
 void Worker::waitForBuildSlot(GoalPtr goal) {
   DLOG(INFO) << "wait for build slot";
-  if (getNrLocalBuilds() < settings.maxBuildJobs)
+  if (getNrLocalBuilds() < settings.maxBuildJobs) {
     wakeUp(goal); /* we can do it right away */
-  else
+  } else {
     addToWeakGoals(wantingToBuild, goal);
+  }
 }
 
 void Worker::waitForAnyGoal(GoalPtr goal) {
@@ -4441,13 +4600,14 @@ void Worker::run(const Goals& _topGoals) {
     }
 
     /* Wait for input. */
-    if (!children.empty() || !waitingForAWhile.empty())
+    if (!children.empty() || !waitingForAWhile.empty()) {
       waitForInput();
-    else {
-      if (awake.empty() && 0 == settings.maxBuildJobs)
+    } else {
+      if (awake.empty() && 0 == settings.maxBuildJobs) {
         throw Error(
             "unable to start any build; either increase '--max-jobs' "
             "or enable remote builds");
+      }
       assert(!awake.empty());
     }
   }
@@ -4478,19 +4638,22 @@ void Worker::waitForInput() {
      is a build timeout, then wait for input until the first
      deadline for any child. */
   auto nearest = steady_time_point::max();  // nearest deadline
-  if (settings.minFree.get() != 0)
+  if (settings.minFree.get() != 0) {
     // Periodicallty wake up to see if we need to run the garbage collector.
     nearest = before + std::chrono::seconds(10);
+  }
   for (auto& i : children) {
     if (!i.respectTimeouts) {
       continue;
     }
-    if (0 != settings.maxSilentTime)
+    if (0 != settings.maxSilentTime) {
       nearest = std::min(
           nearest, i.lastOutput + std::chrono::seconds(settings.maxSilentTime));
-    if (0 != settings.buildTimeout)
+    }
+    if (0 != settings.buildTimeout) {
       nearest = std::min(
           nearest, i.timeStarted + std::chrono::seconds(settings.buildTimeout));
+    }
   }
   if (nearest != steady_time_point::max()) {
     timeout.tv_sec = std::max(
@@ -4504,17 +4667,20 @@ void Worker::waitForInput() {
      up after a few seconds at most. */
   if (!waitingForAWhile.empty()) {
     useTimeout = true;
-    if (lastWokenUp == steady_time_point::min())
+    if (lastWokenUp == steady_time_point::min()) {
       DLOG(WARNING) << "waiting for locks or build slots...";
-    if (lastWokenUp == steady_time_point::min() || lastWokenUp > before)
+    }
+    if (lastWokenUp == steady_time_point::min() || lastWokenUp > before) {
       lastWokenUp = before;
+    }
     timeout.tv_sec = std::max(
         1L,
         (long)std::chrono::duration_cast<std::chrono::seconds>(
             lastWokenUp + std::chrono::seconds(settings.pollInterval) - before)
             .count());
-  } else
+  } else {
     lastWokenUp = steady_time_point::min();
+  }
 
   if (useTimeout) {
     DLOG(INFO) << "sleeping " << timeout.tv_sec << " seconds";
@@ -4570,8 +4736,9 @@ void Worker::waitForInput() {
           goal->handleEOF(k);
           j->fds.erase(k);
         } else if (rd == -1) {
-          if (errno != EINTR)
+          if (errno != EINTR) {
             throw SysError("%s: read failed", goal->getName());
+          }
         } else {
           DLOG(INFO) << goal->getName() << ": read " << rd << " bytes";
           string data((char*)buffer.data(), rd);
@@ -4676,12 +4843,14 @@ static void primeCache(Store& store, const PathSet& paths) {
   store.queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize,
                      narSize);
 
-  if (!willBuild.empty() && 0 == settings.maxBuildJobs && getMachines().empty())
+  if (!willBuild.empty() && 0 == settings.maxBuildJobs &&
+      getMachines().empty()) {
     throw Error(
         "%d derivations need to be built, but neither local builds "
         "('--max-jobs') "
         "nor remote builds ('--builders') are enabled",
         willBuild.size());
+  }
 }
 
 void LocalStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
@@ -4692,11 +4861,12 @@ void LocalStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
   Goals goals;
   for (auto& i : drvPaths) {
     DrvPathWithOutputs i2 = parseDrvPathWithOutputs(i);
-    if (isDerivation(i2.first))
+    if (isDerivation(i2.first)) {
       goals.insert(worker.makeDerivationGoal(i2.first, i2.second, buildMode));
-    else
+    } else {
       goals.insert(worker.makeSubstitutionGoal(
           i, buildMode == bmRepair ? Repair : NoRepair));
+    }
   }
 
   worker.run(goals);
@@ -4705,15 +4875,17 @@ void LocalStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
   for (auto& i : goals) {
     if (i->getExitCode() != Goal::ecSuccess) {
       DerivationGoal* i2 = dynamic_cast<DerivationGoal*>(i.get());
-      if (i2)
+      if (i2) {
         failed.insert(i2->getDrvPath());
-      else
+      } else {
         failed.insert(dynamic_cast<SubstitutionGoal*>(i.get())->getStorePath());
+      }
     }
   }
 
-  if (!failed.empty())
+  if (!failed.empty()) {
     throw Error(worker.exitStatus(), "build of %s failed", showPaths(failed));
+  }
 }
 
 BuildResult LocalStore::buildDerivation(const Path& drvPath,
@@ -4749,9 +4921,10 @@ void LocalStore::ensurePath(const Path& path) {
 
   worker.run(goals);
 
-  if (goal->getExitCode() != Goal::ecSuccess)
+  if (goal->getExitCode() != Goal::ecSuccess) {
     throw Error(worker.exitStatus(),
                 "path '%s' does not exist and cannot be created", path);
+  }
 }
 
 void LocalStore::repairPath(const Path& path) {
@@ -4769,8 +4942,9 @@ void LocalStore::repairPath(const Path& path) {
       goals.clear();
       goals.insert(worker.makeDerivationGoal(deriver, StringSet(), bmRepair));
       worker.run(goals);
-    } else
+    } else {
       throw Error(worker.exitStatus(), "cannot repair path '%s'", path);
+    }
   }
 }
 
diff --git a/third_party/nix/src/libstore/crypto.cc b/third_party/nix/src/libstore/crypto.cc
index 7a169107c1..f26cabdf6d 100644
--- a/third_party/nix/src/libstore/crypto.cc
+++ b/third_party/nix/src/libstore/crypto.cc
@@ -32,8 +32,9 @@ Key::Key(const string& s) {
 
 SecretKey::SecretKey(const string& s) : Key(s) {
 #if HAVE_SODIUM
-  if (key.size() != crypto_sign_SECRETKEYBYTES)
+  if (key.size() != crypto_sign_SECRETKEYBYTES) {
     throw Error("secret key is not valid");
+  }
 #endif
 }
 
@@ -69,8 +70,9 @@ PublicKey SecretKey::toPublicKey() const {
 
 PublicKey::PublicKey(const string& s) : Key(s) {
 #if HAVE_SODIUM
-  if (key.size() != crypto_sign_PUBLICKEYBYTES)
+  if (key.size() != crypto_sign_PUBLICKEYBYTES) {
     throw Error("public key is not valid");
+  }
 #endif
 }
 
diff --git a/third_party/nix/src/libstore/derivations.cc b/third_party/nix/src/libstore/derivations.cc
index 51bcfbe1ce..1b6f160653 100644
--- a/third_party/nix/src/libstore/derivations.cc
+++ b/third_party/nix/src/libstore/derivations.cc
@@ -19,16 +19,18 @@ void DerivationOutput::parseHashInfo(bool& recursive, Hash& hash) const {
   }
 
   HashType hashType = parseHashType(algo);
-  if (hashType == htUnknown)
+  if (hashType == htUnknown) {
     throw Error(format("unknown hash algorithm '%1%'") % algo);
+  }
 
   hash = Hash(this->hash, hashType);
 }
 
 Path BasicDerivation::findOutput(const string& id) const {
   auto i = outputs.find(id);
-  if (i == outputs.end())
+  if (i == outputs.end()) {
     throw Error(format("derivation has no output '%1%'") % id);
+  }
   return i->second.path;
 }
 
@@ -57,8 +59,9 @@ Path writeDerivation(ref<Store> store, const Derivation& drv,
 static void expect(std::istream& str, const string& s) {
   char s2[s.size()];
   str.read(s2, s.size());
-  if (string(s2, s.size()) != s)
+  if (string(s2, s.size()) != s) {
     throw FormatError(format("expected string '%1%'") % s);
+  }
 }
 
 /* Read a C-style string from stream `str'. */
@@ -66,26 +69,30 @@ static string parseString(std::istream& str) {
   string res;
   expect(str, "\"");
   int c;
-  while ((c = str.get()) != '"')
+  while ((c = str.get()) != '"') {
     if (c == '\\') {
       c = str.get();
-      if (c == 'n')
+      if (c == 'n') {
         res += '\n';
-      else if (c == 'r')
+      } else if (c == 'r') {
         res += '\r';
-      else if (c == 't')
+      } else if (c == 't') {
         res += '\t';
-      else
+      } else {
         res += c;
-    } else
+      }
+    } else {
       res += c;
+    }
+  }
   return res;
 }
 
 static Path parsePath(std::istream& str) {
   string s = parseString(str);
-  if (s.size() == 0 || s[0] != '/')
+  if (s.size() == 0 || s[0] != '/') {
     throw FormatError(format("bad path '%1%' in derivation") % s);
+  }
   return s;
 }
 
@@ -103,8 +110,9 @@ static bool endOfList(std::istream& str) {
 
 static StringSet parseStrings(std::istream& str, bool arePaths) {
   StringSet res;
-  while (!endOfList(str))
+  while (!endOfList(str)) {
     res.insert(arePaths ? parsePath(str) : parseString(str));
+  }
   return res;
 }
 
@@ -147,7 +155,9 @@ static Derivation parseDerivation(const string& s) {
 
   /* Parse the builder arguments. */
   expect(str, ",[");
-  while (!endOfList(str)) drv.args.push_back(parseString(str));
+  while (!endOfList(str)) {
+    drv.args.push_back(parseString(str));
+  }
 
   /* Parse the environment variables. */
   expect(str, ",[");
diff --git a/third_party/nix/src/libstore/download.cc b/third_party/nix/src/libstore/download.cc
index fbc2069c08..4b90a37657 100644
--- a/third_party/nix/src/libstore/download.cc
+++ b/third_party/nix/src/libstore/download.cc
@@ -36,11 +36,12 @@ DownloadSettings downloadSettings;
 static GlobalConfig::Register r1(&downloadSettings);
 
 std::string resolveUri(const std::string& uri) {
-  if (uri.compare(0, 8, "channel:") == 0)
+  if (uri.compare(0, 8, "channel:") == 0) {
     return "https://nixos.org/channels/" + std::string(uri, 8) +
            "/nixexprs.tar.xz";
-  else
+  } else {
     return uri;
+  }
 }
 
 struct CurlDownloader : public Downloader {
@@ -92,18 +93,21 @@ struct CurlDownloader : public Downloader {
                 writtenToSink += len;
                 this->request.dataCallback((char*)data, len);
               }
-            } else
+            } else {
               this->result.data->append((char*)data, len);
+            }
           }) {
       LOG(INFO) << (request.data ? "uploading '" : "downloading '")
                 << request.uri << "'";
 
-      if (!request.expectedETag.empty())
+      if (!request.expectedETag.empty()) {
         requestHeaders = curl_slist_append(
             requestHeaders, ("If-None-Match: " + request.expectedETag).c_str());
-      if (!request.mimeType.empty())
+      }
+      if (!request.mimeType.empty()) {
         requestHeaders = curl_slist_append(
             requestHeaders, ("Content-Type: " + request.mimeType).c_str());
+      }
     }
 
     ~DownloadItem() {
@@ -117,10 +121,11 @@ struct CurlDownloader : public Downloader {
         curl_slist_free_all(requestHeaders);
       }
       try {
-        if (!done)
+        if (!done) {
           fail(DownloadError(
               Interrupted,
               format("download of '%s' was interrupted") % request.uri));
+        }
       } catch (...) {
         ignoreException();
       }
@@ -147,8 +152,9 @@ struct CurlDownloader : public Downloader {
         size_t realSize = size * nmemb;
         result.bodySize += realSize;
 
-        if (!decompressionSink)
+        if (!decompressionSink) {
           decompressionSink = makeDecompressionSink(encoding, finalSink);
+        }
 
         (*decompressionSink)((unsigned char*)contents, realSize);
 
@@ -192,11 +198,12 @@ struct CurlDownloader : public Downloader {
                   << "shutting down on 200 HTTP response with expected ETag";
               return 0;
             }
-          } else if (name == "content-encoding")
+          } else if (name == "content-encoding") {
             encoding = trim(string(line, i + 1));
-          else if (name == "accept-ranges" &&
-                   toLower(trim(std::string(line, i + 1))) == "bytes")
+          } else if (name == "accept-ranges" &&
+                     toLower(trim(std::string(line, i + 1))) == "bytes") {
             acceptRanges = true;
+          }
         }
       }
       return realSize;
@@ -275,10 +282,11 @@ struct CurlDownloader : public Downloader {
       curl_easy_setopt(req, CURLOPT_PIPEWAIT, 1);
 #endif
 #if LIBCURL_VERSION_NUM >= 0x072f00
-      if (downloadSettings.enableHttp2)
+      if (downloadSettings.enableHttp2) {
         curl_easy_setopt(req, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS);
-      else
+      } else {
         curl_easy_setopt(req, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
+      }
 #endif
       curl_easy_setopt(req, CURLOPT_WRITEFUNCTION,
                        DownloadItem::writeCallbackWrapper);
@@ -306,8 +314,9 @@ struct CurlDownloader : public Downloader {
       }
 
       if (request.verifyTLS) {
-        if (settings.caFile != "")
+        if (settings.caFile != "") {
           curl_easy_setopt(req, CURLOPT_CAINFO, settings.caFile.c_str());
+        }
       } else {
         curl_easy_setopt(req, CURLOPT_SSL_VERIFYPEER, 0);
         curl_easy_setopt(req, CURLOPT_SSL_VERIFYHOST, 0);
@@ -362,14 +371,14 @@ struct CurlDownloader : public Downloader {
         httpStatus = 304;
       }
 
-      if (writeException)
+      if (writeException) {
         failEx(writeException);
 
-      else if (code == CURLE_OK &&
-               (httpStatus == 200 || httpStatus == 201 || httpStatus == 204 ||
-                httpStatus == 206 || httpStatus == 304 ||
-                httpStatus == 226 /* FTP */ ||
-                httpStatus == 0 /* other protocol */)) {
+      } else if (code == CURLE_OK &&
+                 (httpStatus == 200 || httpStatus == 201 || httpStatus == 204 ||
+                  httpStatus == 206 || httpStatus == 304 ||
+                  httpStatus == 226 /* FTP */ ||
+                  httpStatus == 0 /* other protocol */)) {
         result.cached = httpStatus == 304;
         done = true;
         callback(std::move(result));
@@ -464,8 +473,9 @@ struct CurlDownloader : public Downloader {
           embargo =
               std::chrono::steady_clock::now() + std::chrono::milliseconds(ms);
           downloader.enqueueItem(shared_from_this());
-        } else
+        } else {
           fail(exc);
+        }
       }
     }
   };
@@ -548,10 +558,11 @@ struct CurlDownloader : public Downloader {
       /* Let curl do its thing. */
       int running;
       CURLMcode mc = curl_multi_perform(curlm, &running);
-      if (mc != CURLM_OK)
+      if (mc != CURLM_OK) {
         throw nix::Error(
             format("unexpected error from curl_multi_perform(): %s") %
             curl_multi_strerror(mc));
+      }
 
       /* Set the promises of any finished requests. */
       CURLMsg* msg;
@@ -584,9 +595,10 @@ struct CurlDownloader : public Downloader {
               : maxSleepTimeMs;
       DLOG(INFO) << "download thread waiting for " << sleepTimeMs << " ms";
       mc = curl_multi_wait(curlm, extraFDs, 1, sleepTimeMs, &numfds);
-      if (mc != CURLM_OK)
+      if (mc != CURLM_OK) {
         throw nix::Error(format("unexpected error from curl_multi_wait(): %s") %
                          curl_multi_strerror(mc));
+      }
 
       nextWakeup = std::chrono::steady_clock::time_point();
 
@@ -596,8 +608,9 @@ struct CurlDownloader : public Downloader {
       if (extraFDs[0].revents & CURL_WAIT_POLLIN) {
         char buf[1024];
         auto res = read(extraFDs[0].fd, buf, sizeof(buf));
-        if (res == -1 && errno != EINTR)
+        if (res == -1 && errno != EINTR) {
           throw SysError("reading curl wakeup socket");
+        }
       }
 
       std::vector<std::shared_ptr<DownloadItem>> incoming;
@@ -612,8 +625,9 @@ struct CurlDownloader : public Downloader {
             state->incoming.pop();
           } else {
             if (nextWakeup == std::chrono::steady_clock::time_point() ||
-                item->embargo < nextWakeup)
+                item->embargo < nextWakeup) {
               nextWakeup = item->embargo;
+            }
             break;
           }
         }
@@ -643,22 +657,26 @@ struct CurlDownloader : public Downloader {
 
     {
       auto state(state_.lock());
-      while (!state->incoming.empty()) state->incoming.pop();
+      while (!state->incoming.empty()) {
+        state->incoming.pop();
+      }
       state->quit = true;
     }
   }
 
   void enqueueItem(std::shared_ptr<DownloadItem> item) {
     if (item->request.data && !hasPrefix(item->request.uri, "http://") &&
-        !hasPrefix(item->request.uri, "https://"))
+        !hasPrefix(item->request.uri, "https://")) {
       throw nix::Error("uploading to '%s' is not supported", item->request.uri);
+    }
 
     {
       auto state(state_.lock());
-      if (state->quit)
+      if (state->quit) {
         throw nix::Error(
             "cannot enqueue download request because the download thread is "
             "shutting down");
+      }
       state->incoming.push(item);
     }
     writeFull(wakeupPipe.writeSide.get(), " ");
@@ -900,8 +918,9 @@ CachedDownloadResult Downloader::downloadCached(
           expectedETag = ss[1];
         }
       }
-    } else
+    } else {
       storePath = "";
+    }
   }
 
   if (!skip) {
diff --git a/third_party/nix/src/libstore/export-import.cc b/third_party/nix/src/libstore/export-import.cc
index 930ff90d26..6a1862492d 100644
--- a/third_party/nix/src/libstore/export-import.cc
+++ b/third_party/nix/src/libstore/export-import.cc
@@ -46,9 +46,10 @@ void Store::exportPath(const Path& path, Sink& sink) {
      filesystem corruption from spreading to other machines.
      Don't complain if the stored hash is zero (unknown). */
   Hash hash = hashAndWriteSink.currentHash();
-  if (hash != info->narHash && info->narHash != Hash(info->narHash.type))
+  if (hash != info->narHash && info->narHash != Hash(info->narHash.type)) {
     throw Error(format("hash of path '%1%' has changed from '%2%' to '%3%'!") %
                 path % info->narHash.to_string() % hash.to_string());
+  }
 
   hashAndWriteSink << exportMagic << path << info->references << info->deriver
                    << 0;
@@ -62,17 +63,19 @@ Paths Store::importPaths(Source& source, std::shared_ptr<FSAccessor> accessor,
     if (n == 0) {
       break;
     }
-    if (n != 1)
+    if (n != 1) {
       throw Error(
           "input doesn't look like something created by 'nix-store --export'");
+    }
 
     /* Extract the NAR from the source. */
     TeeSink tee(source);
     parseDump(tee, tee.source);
 
     uint32_t magic = readInt(source);
-    if (magic != exportMagic)
+    if (magic != exportMagic) {
       throw Error("Nix archive cannot be imported; wrong format");
+    }
 
     ValidPathInfo info;
 
diff --git a/third_party/nix/src/libstore/gc.cc b/third_party/nix/src/libstore/gc.cc
index c7f2a507d3..3e79e6c336 100644
--- a/third_party/nix/src/libstore/gc.cc
+++ b/third_party/nix/src/libstore/gc.cc
@@ -61,8 +61,9 @@ static void makeSymlink(const Path& link, const Path& target) {
   createSymlink(target, tempLink);
 
   /* Atomically replace the old one. */
-  if (rename(tempLink.c_str(), link.c_str()) == -1)
+  if (rename(tempLink.c_str(), link.c_str()) == -1) {
     throw SysError(format("cannot rename '%1%' to '%2%'") % tempLink % link);
+  }
 }
 
 void LocalStore::syncWithGC() { AutoCloseFD fdGCLock = openGCLock(ltRead); }
@@ -80,18 +81,21 @@ Path LocalFSStore::addPermRoot(const Path& _storePath, const Path& _gcRoot,
   Path gcRoot(canonPath(_gcRoot));
   assertStorePath(storePath);
 
-  if (isInStore(gcRoot))
+  if (isInStore(gcRoot)) {
     throw Error(format("creating a garbage collector root (%1%) in the Nix "
                        "store is forbidden "
                        "(are you running nix-build inside the store?)") %
                 gcRoot);
+  }
 
   if (indirect) {
     /* Don't clobber the link if it already exists and doesn't
        point to the Nix store. */
-    if (pathExists(gcRoot) && (!isLink(gcRoot) || !isInStore(readLink(gcRoot))))
+    if (pathExists(gcRoot) &&
+        (!isLink(gcRoot) || !isInStore(readLink(gcRoot)))) {
       throw Error(format("cannot create symlink '%1%'; already exists") %
                   gcRoot);
+    }
     makeSymlink(gcRoot, storePath);
     addIndirectRoot(gcRoot);
   }
@@ -101,16 +105,18 @@ Path LocalFSStore::addPermRoot(const Path& _storePath, const Path& _gcRoot,
       Path rootsDir =
           canonPath((format("%1%/%2%") % stateDir % gcRootsDir).str());
 
-      if (string(gcRoot, 0, rootsDir.size() + 1) != rootsDir + "/")
+      if (string(gcRoot, 0, rootsDir.size() + 1) != rootsDir + "/") {
         throw Error(format("path '%1%' is not a valid garbage collector root; "
                            "it's not in the directory '%2%'") %
                     gcRoot % rootsDir);
+      }
     }
 
-    if (baseNameOf(gcRoot) == baseNameOf(storePath))
+    if (baseNameOf(gcRoot) == baseNameOf(storePath)) {
       writeFile(gcRoot, "");
-    else
+    } else {
       makeSymlink(gcRoot, storePath);
+    }
   }
 
   /* Check that the root can be found by the garbage collector.
@@ -144,10 +150,11 @@ void LocalStore::addTempRoot(const Path& path) {
     while (1) {
       AutoCloseFD fdGCLock = openGCLock(ltRead);
 
-      if (pathExists(fnTempRoots))
+      if (pathExists(fnTempRoots)) {
         /* It *must* be stale, since there can be no two
            processes with the same pid. */
         unlink(fnTempRoots.c_str());
+      }
 
       state->fdTempRoots = openLockFile(fnTempRoots, true);
 
@@ -159,8 +166,9 @@ void LocalStore::addTempRoot(const Path& path) {
       /* Check whether the garbage collector didn't get in our
          way. */
       struct stat st;
-      if (fstat(state->fdTempRoots.get(), &st) == -1)
+      if (fstat(state->fdTempRoots.get(), &st) == -1) {
         throw SysError(format("statting '%1%'") % fnTempRoots);
+      }
       if (st.st_size == 0) {
         break;
       }
@@ -245,11 +253,12 @@ void LocalStore::findTempRoots(FDs& fds, Roots& tempRoots, bool censor) {
 void LocalStore::findRoots(const Path& path, unsigned char type, Roots& roots) {
   auto foundRoot = [&](const Path& path, const Path& target) {
     Path storePath = toStorePath(target);
-    if (isStorePath(storePath) && isValidPath(storePath))
+    if (isStorePath(storePath) && isValidPath(storePath)) {
       roots[storePath].emplace(path);
-    else
+    } else {
       LOG(INFO) << "skipping invalid root from '" << path << "' to '"
                 << storePath << "'";
+    }
   };
 
   try {
@@ -258,8 +267,9 @@ void LocalStore::findRoots(const Path& path, unsigned char type, Roots& roots) {
     }
 
     if (type == DT_DIR) {
-      for (auto& i : readDirectory(path))
+      for (auto& i : readDirectory(path)) {
         findRoots(path + "/" + i.name, i.type, roots);
+      }
     }
 
     else if (type == DT_LNK) {
@@ -292,8 +302,9 @@ void LocalStore::findRoots(const Path& path, unsigned char type, Roots& roots) {
 
     else if (type == DT_REG) {
       Path storePath = storeDir + "/" + baseNameOf(path);
-      if (isStorePath(storePath) && isValidPath(storePath))
+      if (isStorePath(storePath) && isValidPath(storePath)) {
         roots[storePath].emplace(path);
+      }
     }
 
   }
@@ -395,8 +406,9 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
         }
         struct dirent* fd_ent;
         while (errno = 0, fd_ent = readdir(fdDir.get())) {
-          if (fd_ent->d_name[0] != '.')
+          if (fd_ent->d_name[0] != '.') {
             readProcLink(fmt("%s/%s", fdStr, fd_ent->d_name), unchecked);
+          }
         }
         if (errno) {
           if (errno == ESRCH) {
@@ -412,8 +424,9 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
               readFile(mapFile, true), "\n");
           for (const auto& line : mapLines) {
             auto match = std::smatch{};
-            if (std::regex_match(line, match, mapRegex))
+            if (std::regex_match(line, match, mapRegex)) {
               unchecked[match[1]].emplace(mapFile);
+            }
           }
 
           auto envFile = fmt("/proc/%s/environ", ent->d_name);
@@ -421,8 +434,9 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
           auto env_end = std::sregex_iterator{};
           for (auto i = std::sregex_iterator{envString.begin(), envString.end(),
                                              storePathRegex};
-               i != env_end; ++i)
+               i != env_end; ++i) {
             unchecked[i->str()].emplace(envFile);
+          }
         } catch (SysError& e) {
           if (errno == ENOENT || errno == EACCES || errno == ESRCH) {
             continue;
@@ -467,10 +481,11 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
       Path path = toStorePath(target);
       if (isStorePath(path) && isValidPath(path)) {
         DLOG(INFO) << "got additional root " << path;
-        if (censor)
+        if (censor) {
           roots[path].insert(censored);
-        else
+        } else {
           roots[path].insert(links.begin(), links.end());
+        }
       }
     }
   }
@@ -514,10 +529,11 @@ void LocalStore::deletePathRecursive(GCState& state, const Path& path) {
   if (isStorePath(path) && isValidPath(path)) {
     PathSet referrers;
     queryReferrers(path, referrers);
-    for (auto& i : referrers)
+    for (auto& i : referrers) {
       if (i != path) {
         deletePathRecursive(state, i);
       }
+    }
     size = queryPathInfo(path)->narSize;
     invalidatePathChecked(path);
   }
@@ -546,12 +562,14 @@ void LocalStore::deletePathRecursive(GCState& state, const Path& path) {
     // if the path was not valid, need to determine the actual
     // size.
     try {
-      if (chmod(realPath.c_str(), st.st_mode | S_IWUSR) == -1)
+      if (chmod(realPath.c_str(), st.st_mode | S_IWUSR) == -1) {
         throw SysError(format("making '%1%' writable") % realPath);
+      }
       Path tmp = trashDir + "/" + baseNameOf(path);
-      if (rename(realPath.c_str(), tmp.c_str()))
+      if (rename(realPath.c_str(), tmp.c_str())) {
         throw SysError(format("unable to rename '%1%' to '%2%'") % realPath %
                        tmp);
+      }
       state.bytesInvalidated += size;
     } catch (SysError& e) {
       if (e.errNo == ENOSPC) {
@@ -560,8 +578,9 @@ void LocalStore::deletePathRecursive(GCState& state, const Path& path) {
         deleteGarbage(state, realPath);
       }
     }
-  } else
+  } else {
     deleteGarbage(state, realPath);
+  }
 
   if (state.results.bytesFreed + state.bytesInvalidated >
       state.options.maxFreed) {
@@ -606,9 +625,11 @@ bool LocalStore::canReachRoot(GCState& state, PathSet& visited,
      don't delete the derivation if any of the outputs are alive. */
   if (state.gcKeepDerivations && isDerivation(path)) {
     PathSet outputs = queryDerivationOutputs(path);
-    for (auto& i : outputs)
-      if (isValidPath(i) && queryPathInfo(i)->deriver == path)
+    for (auto& i : outputs) {
+      if (isValidPath(i) && queryPathInfo(i)->deriver == path) {
         incoming.insert(i);
+      }
+    }
   }
 
   /* If keep-outputs is set, then don't delete this path if there
@@ -620,12 +641,14 @@ bool LocalStore::canReachRoot(GCState& state, PathSet& visited,
     }
   }
 
-  for (auto& i : incoming)
-    if (i != path)
+  for (auto& i : incoming) {
+    if (i != path) {
       if (canReachRoot(state, visited, i)) {
         state.alive.insert(path);
         return true;
       }
+    }
+  }
 
   return false;
 }
@@ -701,8 +724,9 @@ void LocalStore::removeUnusedLinks(const GCState& state) {
     Path path = linksDir + "/" + name;
 
     struct stat st;
-    if (lstat(path.c_str(), &st) == -1)
+    if (lstat(path.c_str(), &st) == -1) {
       throw SysError(format("statting '%1%'") % path);
+    }
 
     if (st.st_nlink != 1) {
       actualSize += st.st_size;
@@ -807,16 +831,18 @@ void LocalStore::collectGarbage(const GCOptions& options, GCResults& results) {
     for (auto& i : options.pathsToDelete) {
       assertStorePath(i);
       tryToDelete(state, i);
-      if (state.dead.find(i) == state.dead.end())
+      if (state.dead.find(i) == state.dead.end()) {
         throw Error(format("cannot delete path '%1%' since it is still alive") %
                     i);
+      }
     }
 
   } else if (options.maxFreed > 0) {
-    if (state.shouldDelete)
+    if (state.shouldDelete) {
       LOG(INFO) << "deleting garbage...";
-    else
+    } else {
       LOG(ERROR) << "determining live/dead paths...";
+    }
 
     try {
       AutoCloseDir dir(opendir(realStoreDir.c_str()));
@@ -839,10 +865,11 @@ void LocalStore::collectGarbage(const GCOptions& options, GCResults& results) {
           continue;
         }
         Path path = storeDir + "/" + name;
-        if (isStorePath(path) && isValidPath(path))
+        if (isStorePath(path) && isValidPath(path)) {
           entries.push_back(path);
-        else
+        } else {
           tryToDelete(state, path);
+        }
       }
 
       dir.reset();
@@ -897,8 +924,9 @@ void LocalStore::autoGC(bool sync) {
   static auto fakeFreeSpaceFile = getEnv("_NIX_TEST_FREE_SPACE_FILE", "");
 
   auto getAvail = [this]() -> uint64_t {
-    if (!fakeFreeSpaceFile.empty())
+    if (!fakeFreeSpaceFile.empty()) {
       return std::stoll(readFile(fakeFreeSpaceFile));
+    }
 
     struct statvfs st;
     if (statvfs(realStoreDir.c_str(), &st)) {
@@ -922,8 +950,9 @@ void LocalStore::autoGC(bool sync) {
     auto now = std::chrono::steady_clock::now();
 
     if (now < state->lastGCCheck +
-                  std::chrono::seconds(settings.minFreeCheckInterval))
+                  std::chrono::seconds(settings.minFreeCheckInterval)) {
       return;
+    }
 
     auto avail = getAvail();
 
diff --git a/third_party/nix/src/libstore/globals.cc b/third_party/nix/src/libstore/globals.cc
index 19a0cde1ed..ade200f135 100644
--- a/third_party/nix/src/libstore/globals.cc
+++ b/third_party/nix/src/libstore/globals.cc
@@ -49,11 +49,12 @@ Settings::Settings()
   if (caFile == "") {
     for (auto& fn :
          {"/etc/ssl/certs/ca-certificates.crt",
-          "/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"})
+          "/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"}) {
       if (pathExists(fn)) {
         caFile = fn;
         break;
       }
+    }
   }
 
   /* Backwards compatibility. */
@@ -112,26 +113,28 @@ const string nixVersion = PACKAGE_VERSION;
 
 template <>
 void BaseSetting<SandboxMode>::set(const std::string& str) {
-  if (str == "true")
+  if (str == "true") {
     value = smEnabled;
-  else if (str == "relaxed")
+  } else if (str == "relaxed") {
     value = smRelaxed;
-  else if (str == "false")
+  } else if (str == "false") {
     value = smDisabled;
-  else
+  } else {
     throw UsageError("option '%s' has invalid value '%s'", name, str);
+  }
 }
 
 template <>
 std::string BaseSetting<SandboxMode>::to_string() {
-  if (value == smEnabled)
+  if (value == smEnabled) {
     return "true";
-  else if (value == smRelaxed)
+  } else if (value == smRelaxed) {
     return "relaxed";
-  else if (value == smDisabled)
+  } else if (value == smDisabled) {
     return "false";
-  else
+  } else {
     abort();
+  }
 }
 
 template <>
@@ -160,11 +163,12 @@ void BaseSetting<SandboxMode>::convertToArg(Args& args,
 }
 
 void MaxBuildJobsSetting::set(const std::string& str) {
-  if (str == "auto")
+  if (str == "auto") {
     value = std::max(1U, std::thread::hardware_concurrency());
-  else if (!string2Int(str, value))
+  } else if (!string2Int(str, value)) {
     throw UsageError(
         "configuration setting '%s' should be 'auto' or an integer", name);
+  }
 }
 
 void initPlugins() {
@@ -172,8 +176,9 @@ void initPlugins() {
     Paths pluginFiles;
     try {
       auto ents = readDirectory(pluginFile);
-      for (const auto& ent : ents)
+      for (const auto& ent : ents) {
         pluginFiles.emplace_back(pluginFile + "/" + ent.name);
+      }
     } catch (SysError& e) {
       if (e.errNo != ENOTDIR) {
         throw;
@@ -184,9 +189,10 @@ void initPlugins() {
       /* handle is purposefully leaked as there may be state in the
          DSO needed by the action of the plugin. */
       void* handle = dlopen(file.c_str(), RTLD_LAZY | RTLD_LOCAL);
-      if (!handle)
+      if (!handle) {
         throw Error("could not dynamically open plugin file '%s': %s", file,
                     dlerror());
+      }
     }
   }
 
diff --git a/third_party/nix/src/libstore/globals.hh b/third_party/nix/src/libstore/globals.hh
index 7b4d614f7a..924e8a0165 100644
--- a/third_party/nix/src/libstore/globals.hh
+++ b/third_party/nix/src/libstore/globals.hh
@@ -408,17 +408,10 @@ class Settings : public Config {
       this, true, "print-missing",
       "Whether to print what paths need to be built or downloaded."};
 
-  Setting<std::string> preBuildHook {
-    this,
-#if __APPLE__
-        nixLibexecDir + "/nix/resolve-system-dependencies",
-#else
-        "",
-#endif
-        "pre-build-hook",
-        "A program to run just before a build to set derivation-specific build "
-        "settings."
-  };
+  Setting<std::string> preBuildHook{
+      this, "", "pre-build-hook",
+      "A program to run just before a build to set derivation-specific build "
+      "settings."};
 
   Setting<std::string> postBuildHook{
       this, "", "post-build-hook",
diff --git a/third_party/nix/src/libstore/http-binary-cache-store.cc b/third_party/nix/src/libstore/http-binary-cache-store.cc
index 2482b02c61..d3b551f08c 100644
--- a/third_party/nix/src/libstore/http-binary-cache-store.cc
+++ b/third_party/nix/src/libstore/http-binary-cache-store.cc
@@ -113,9 +113,10 @@ class HttpBinaryCacheStore : public BinaryCacheStore {
     try {
       getDownloader()->download(std::move(request), sink);
     } catch (DownloadError& e) {
-      if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden)
+      if (e.error == Downloader::NotFound || e.error == Downloader::Forbidden) {
         throw NoSuchBinaryCacheFile(
             "file '%s' does not exist in binary cache '%s'", path, getUri());
+      }
       maybeDisable();
       throw;
     }
@@ -137,8 +138,9 @@ class HttpBinaryCacheStore : public BinaryCacheStore {
             (*callbackPtr)(result.get().data);
           } catch (DownloadError& e) {
             if (e.error == Downloader::NotFound ||
-                e.error == Downloader::Forbidden)
+                e.error == Downloader::Forbidden) {
               return (*callbackPtr)(std::shared_ptr<std::string>());
+            }
             maybeDisable();
             callbackPtr->rethrow();
           } catch (...) {
@@ -154,8 +156,9 @@ static RegisterStoreImplementation regStore(
       if (std::string(uri, 0, 7) != "http://" &&
           std::string(uri, 0, 8) != "https://" &&
           (getEnv("_NIX_FORCE_HTTP_BINARY_CACHE_STORE") != "1" ||
-           std::string(uri, 0, 7) != "file://"))
+           std::string(uri, 0, 7) != "file://")) {
         return 0;
+      }
       auto store = std::make_shared<HttpBinaryCacheStore>(params, uri);
       store->init();
       return store;
diff --git a/third_party/nix/src/libstore/legacy-ssh-store.cc b/third_party/nix/src/libstore/legacy-ssh-store.cc
index 8510895d0b..0cfe1bfe5d 100644
--- a/third_party/nix/src/libstore/legacy-ssh-store.cc
+++ b/third_party/nix/src/libstore/legacy-ssh-store.cc
@@ -69,12 +69,14 @@ struct LegacySSHStore : public Store {
       conn->to.flush();
 
       unsigned int magic = readInt(conn->from);
-      if (magic != SERVE_MAGIC_2)
+      if (magic != SERVE_MAGIC_2) {
         throw Error("protocol mismatch with 'nix-store --serve' on '%s'", host);
+      }
       conn->remoteVersion = readInt(conn->from);
-      if (GET_PROTOCOL_MAJOR(conn->remoteVersion) != 0x200)
+      if (GET_PROTOCOL_MAJOR(conn->remoteVersion) != 0x200) {
         throw Error("unsupported 'nix-store --serve' protocol version on '%s'",
                     host);
+      }
 
     } catch (EndOfFile& e) {
       throw Error("cannot connect to '%1%'", host);
@@ -160,9 +162,10 @@ struct LegacySSHStore : public Store {
       conn->to.flush();
     }
 
-    if (readInt(conn->from) != 1)
+    if (readInt(conn->from) != 1) {
       throw Error(
           "failed to add path '%s' to remote host '%s', info.path, host");
+    }
   }
 
   void narFromPath(const Path& path, Sink& sink) override {
@@ -194,10 +197,12 @@ struct LegacySSHStore : public Store {
 
     conn->to << cmdBuildDerivation << drvPath << drv << settings.maxSilentTime
              << settings.buildTimeout;
-    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 2)
+    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 2) {
       conn->to << settings.maxLogSize;
-    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3)
+    }
+    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3) {
       conn->to << settings.buildRepeat << settings.enforceDeterminism;
+    }
 
     conn->to.flush();
 
@@ -205,9 +210,10 @@ struct LegacySSHStore : public Store {
     status.status = (BuildResult::Status)readInt(conn->from);
     conn->from >> status.errorMsg;
 
-    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3)
+    if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3) {
       conn->from >> status.timesBuilt >> status.isNonDeterministic >>
           status.startTime >> status.stopTime;
+    }
 
     return status;
   }
diff --git a/third_party/nix/src/libstore/local-binary-cache-store.cc b/third_party/nix/src/libstore/local-binary-cache-store.cc
index 925fb34de4..29c74cedd8 100644
--- a/third_party/nix/src/libstore/local-binary-cache-store.cc
+++ b/third_party/nix/src/libstore/local-binary-cache-store.cc
@@ -26,9 +26,10 @@ class LocalBinaryCacheStore : public BinaryCacheStore {
     try {
       readFile(binaryCacheDir + "/" + path, sink);
     } catch (SysError& e) {
-      if (e.errNo == ENOENT)
+      if (e.errNo == ENOENT) {
         throw NoSuchBinaryCacheFile("file '%s' does not exist in binary cache",
                                     path);
+      }
     }
   }
 
@@ -36,8 +37,9 @@ class LocalBinaryCacheStore : public BinaryCacheStore {
     PathSet paths;
 
     for (auto& entry : readDirectory(binaryCacheDir)) {
-      if (entry.name.size() != 40 || !hasSuffix(entry.name, ".narinfo"))
+      if (entry.name.size() != 40 || !hasSuffix(entry.name, ".narinfo")) {
         continue;
+      }
       paths.insert(storeDir + "/" +
                    entry.name.substr(0, entry.name.size() - 8));
     }
@@ -55,8 +57,9 @@ static void atomicWrite(const Path& path, const std::string& s) {
   Path tmp = path + ".tmp." + std::to_string(getpid());
   AutoDelete del(tmp, false);
   writeFile(tmp, s);
-  if (rename(tmp.c_str(), path.c_str()))
+  if (rename(tmp.c_str(), path.c_str())) {
     throw SysError(format("renaming '%1%' to '%2%'") % tmp % path);
+  }
   del.cancel();
 }
 
@@ -74,8 +77,9 @@ static RegisterStoreImplementation regStore(
     [](const std::string& uri,
        const Store::Params& params) -> std::shared_ptr<Store> {
       if (getEnv("_NIX_FORCE_HTTP_BINARY_CACHE_STORE") == "1" ||
-          std::string(uri, 0, 7) != "file://")
+          std::string(uri, 0, 7) != "file://") {
         return 0;
+      }
       auto store =
           std::make_shared<LocalBinaryCacheStore>(params, std::string(uri, 7));
       store->init();
diff --git a/third_party/nix/src/libstore/local-fs-store.cc b/third_party/nix/src/libstore/local-fs-store.cc
index d9eaea2e93..bc282eac96 100644
--- a/third_party/nix/src/libstore/local-fs-store.cc
+++ b/third_party/nix/src/libstore/local-fs-store.cc
@@ -16,9 +16,10 @@ struct LocalStoreAccessor : public FSAccessor {
 
   Path toRealPath(const Path& path) {
     Path storePath = store->toStorePath(path);
-    if (!store->isValidPath(storePath))
+    if (!store->isValidPath(storePath)) {
       throw InvalidPath(format("path '%1%' is not a valid store path") %
                         storePath);
+    }
     return store->getRealStoreDir() + std::string(path, store->storeDir.size());
   }
 
@@ -27,13 +28,15 @@ struct LocalStoreAccessor : public FSAccessor {
 
     struct stat st;
     if (lstat(realPath.c_str(), &st)) {
-      if (errno == ENOENT || errno == ENOTDIR)
+      if (errno == ENOENT || errno == ENOTDIR) {
         return {Type::tMissing, 0, false};
+      }
       throw SysError(format("getting status of '%1%'") % path);
     }
 
-    if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode))
+    if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode) && !S_ISLNK(st.st_mode)) {
       throw Error(format("file '%1%' has unsupported type") % path);
+    }
 
     return {S_ISREG(st.st_mode)
                 ? Type::tRegular
diff --git a/third_party/nix/src/libstore/local-store.cc b/third_party/nix/src/libstore/local-store.cc
index 4c431b6b38..020813a356 100644
--- a/third_party/nix/src/libstore/local-store.cc
+++ b/third_party/nix/src/libstore/local-store.cc
@@ -73,8 +73,9 @@ LocalStore::LocalStore(const Params& params)
   for (auto& perUserDir :
        {profilesDir + "/per-user", gcRootsDir + "/per-user"}) {
     createDirs(perUserDir);
-    if (chmod(perUserDir.c_str(), 0755) == -1)
+    if (chmod(perUserDir.c_str(), 0755) == -1) {
       throw SysError("could not set permissions on '%s' to 755", perUserDir);
+    }
   }
 
   createUser(getUserName(), getuid());
@@ -90,18 +91,21 @@ LocalStore::LocalStore(const Params& params)
                  << "' specified in 'build-users-group' does not exist";
     } else {
       struct stat st;
-      if (stat(realStoreDir.c_str(), &st))
+      if (stat(realStoreDir.c_str(), &st)) {
         throw SysError(format("getting attributes of path '%1%'") %
                        realStoreDir);
+      }
 
       if (st.st_uid != 0 || st.st_gid != gr->gr_gid ||
           (st.st_mode & ~S_IFMT) != perm) {
-        if (chown(realStoreDir.c_str(), 0, gr->gr_gid) == -1)
+        if (chown(realStoreDir.c_str(), 0, gr->gr_gid) == -1) {
           throw SysError(format("changing ownership of path '%1%'") %
                          realStoreDir);
-        if (chmod(realStoreDir.c_str(), perm) == -1)
+        }
+        if (chmod(realStoreDir.c_str(), perm) == -1) {
           throw SysError(format("changing permissions on path '%1%'") %
                          realStoreDir);
+        }
       }
     }
   }
@@ -111,13 +115,15 @@ LocalStore::LocalStore(const Params& params)
     Path path = realStoreDir;
     struct stat st;
     while (path != "/") {
-      if (lstat(path.c_str(), &st))
+      if (lstat(path.c_str(), &st)) {
         throw SysError(format("getting status of '%1%'") % path);
-      if (S_ISLNK(st.st_mode))
+      }
+      if (S_ISLNK(st.st_mode)) {
         throw Error(format("the path '%1%' is a symlink; "
                            "this is not allowed for the Nix store and its "
                            "parent directories") %
                     path);
+      }
       path = dirOf(path);
     }
   }
@@ -168,17 +174,19 @@ LocalStore::LocalStore(const Params& params)
     openDB(*state, true);
     writeFile(schemaPath, (format("%1%") % nixSchemaVersion).str());
   } else if (curSchema < nixSchemaVersion) {
-    if (curSchema < 5)
+    if (curSchema < 5) {
       throw Error(
           "Your Nix store has a database in Berkeley DB format,\n"
           "which is no longer supported. To convert to the new format,\n"
           "please upgrade Nix to version 0.12 first.");
+    }
 
-    if (curSchema < 6)
+    if (curSchema < 6) {
       throw Error(
           "Your Nix store has a database in flat file format,\n"
           "which is no longer supported. To convert to the new format,\n"
           "please upgrade Nix to version 1.11 first.");
+    }
 
     if (!lockFile(globalLock.get(), ltWrite, false)) {
       LOG(INFO) << "waiting for exclusive access to the Nix store...";
@@ -295,24 +303,27 @@ int LocalStore::getSchema() {
   int curSchema = 0;
   if (pathExists(schemaPath)) {
     string s = readFile(schemaPath);
-    if (!string2Int(s, curSchema))
+    if (!string2Int(s, curSchema)) {
       throw Error(format("'%1%' is corrupt") % schemaPath);
+    }
   }
   return curSchema;
 }
 
 void LocalStore::openDB(State& state, bool create) {
-  if (access(dbDir.c_str(), R_OK | W_OK))
+  if (access(dbDir.c_str(), R_OK | W_OK)) {
     throw SysError(format("Nix database directory '%1%' is not writable") %
                    dbDir);
+  }
 
   /* Open the Nix database. */
   string dbPath = dbDir + "/db.sqlite";
   auto& db(state.db);
   if (sqlite3_open_v2(dbPath.c_str(), &db.db,
                       SQLITE_OPEN_READWRITE | (create ? SQLITE_OPEN_CREATE : 0),
-                      0) != SQLITE_OK)
+                      0) != SQLITE_OK) {
     throw Error(format("cannot open Nix database '%1%'") % dbPath);
+  }
 
 #ifdef __CYGWIN__
   /* The cygwin version of sqlite3 has a patch which calls
@@ -354,15 +365,17 @@ void LocalStore::openDB(State& state, bool create) {
   }
   if (prevMode != mode &&
       sqlite3_exec(db, ("pragma main.journal_mode = " + mode + ";").c_str(), 0,
-                   0, 0) != SQLITE_OK)
+                   0, 0) != SQLITE_OK) {
     throwSQLiteError(db, "setting journal mode");
+  }
 
   /* Increase the auto-checkpoint interval to 40000 pages.  This
      seems enough to ensure that instantiating the NixOS system
      derivation is done in a single fsync(). */
   if (mode == "wal" && sqlite3_exec(db, "pragma wal_autocheckpoint = 40000;", 0,
-                                    0, 0) != SQLITE_OK)
+                                    0, 0) != SQLITE_OK) {
     throwSQLiteError(db, "setting autocheckpoint interval");
+  }
 
   /* Initialise the database schema, if necessary. */
   if (create) {
@@ -382,15 +395,18 @@ void LocalStore::makeStoreWritable() {
   }
   /* Check if /nix/store is on a read-only mount. */
   struct statvfs stat;
-  if (statvfs(realStoreDir.c_str(), &stat) != 0)
+  if (statvfs(realStoreDir.c_str(), &stat) != 0) {
     throw SysError("getting info about the Nix store mount point");
+  }
 
   if (stat.f_flag & ST_RDONLY) {
-    if (unshare(CLONE_NEWNS) == -1)
+    if (unshare(CLONE_NEWNS) == -1) {
       throw SysError("setting up a private mount namespace");
+    }
 
-    if (mount(0, realStoreDir.c_str(), "none", MS_REMOUNT | MS_BIND, 0) == -1)
+    if (mount(0, realStoreDir.c_str(), "none", MS_REMOUNT | MS_BIND, 0) == -1) {
       throw SysError(format("remounting %1% writable") % realStoreDir);
+    }
   }
 #endif
 }
@@ -405,8 +421,9 @@ static void canonicaliseTimestampAndPermissions(const Path& path,
 
     if (mode != 0444 && mode != 0555) {
       mode = (st.st_mode & S_IFMT) | 0444 | (st.st_mode & S_IXUSR ? 0111 : 0);
-      if (chmod(path.c_str(), mode) == -1)
+      if (chmod(path.c_str(), mode) == -1) {
         throw SysError(format("changing mode of '%1%' to %2$o") % path % mode);
+      }
     }
   }
 
@@ -417,20 +434,23 @@ static void canonicaliseTimestampAndPermissions(const Path& path,
     times[1].tv_sec = mtimeStore;
     times[1].tv_usec = 0;
 #if HAVE_LUTIMES
-    if (lutimes(path.c_str(), times) == -1)
+    if (lutimes(path.c_str(), times) == -1) {
       if (errno != ENOSYS ||
-          (!S_ISLNK(st.st_mode) && utimes(path.c_str(), times) == -1))
+          (!S_ISLNK(st.st_mode) && utimes(path.c_str(), times) == -1)) {
 #else
     if (!S_ISLNK(st.st_mode) && utimes(path.c_str(), times) == -1)
 #endif
         throw SysError(format("changing modification time of '%1%'") % path);
-  }
+      }
+    }
+  }  // namespace nix
 }
 
 void canonicaliseTimestampAndPermissions(const Path& path) {
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting attributes of path '%1%'") % path);
+  }
   canonicaliseTimestampAndPermissions(path, st);
 }
 
@@ -449,25 +469,29 @@ static void canonicalisePathMetaData_(const Path& path, uid_t fromUid,
 #endif
 
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting attributes of path '%1%'") % path);
+  }
 
   /* Really make sure that the path is of a supported type. */
-  if (!(S_ISREG(st.st_mode) || S_ISDIR(st.st_mode) || S_ISLNK(st.st_mode)))
+  if (!(S_ISREG(st.st_mode) || S_ISDIR(st.st_mode) || S_ISLNK(st.st_mode))) {
     throw Error(format("file '%1%' has an unsupported type") % path);
+  }
 
 #if __linux__
   /* Remove extended attributes / ACLs. */
   ssize_t eaSize = llistxattr(path.c_str(), nullptr, 0);
 
   if (eaSize < 0) {
-    if (errno != ENOTSUP && errno != ENODATA)
+    if (errno != ENOTSUP && errno != ENODATA) {
       throw SysError("querying extended attributes of '%s'", path);
+    }
   } else if (eaSize > 0) {
     std::vector<char> eaBuf(eaSize);
 
-    if ((eaSize = llistxattr(path.c_str(), eaBuf.data(), eaBuf.size())) < 0)
+    if ((eaSize = llistxattr(path.c_str(), eaBuf.data(), eaBuf.size())) < 0) {
       throw SysError("querying extended attributes of '%s'", path);
+    }
 
     for (auto& eaName : tokenizeString<Strings>(
              std::string(eaBuf.data(), eaSize), std::string("\000", 1))) {
@@ -476,9 +500,10 @@ static void canonicalisePathMetaData_(const Path& path, uid_t fromUid,
       if (eaName == "security.selinux") {
         continue;
       }
-      if (lremovexattr(path.c_str(), eaName.c_str()) == -1)
+      if (lremovexattr(path.c_str(), eaName.c_str()) == -1) {
         throw SysError("removing extended attribute '%s' from '%s'", eaName,
                        path);
+      }
     }
   }
 #endif
@@ -491,8 +516,9 @@ static void canonicalisePathMetaData_(const Path& path, uid_t fromUid,
      (i.e. "touch $out/foo; ln $out/foo $out/bar"). */
   if (fromUid != (uid_t)-1 && st.st_uid != fromUid) {
     assert(!S_ISDIR(st.st_mode));
-    if (inodesSeen.find(Inode(st.st_dev, st.st_ino)) == inodesSeen.end())
+    if (inodesSeen.find(Inode(st.st_dev, st.st_ino)) == inodesSeen.end()) {
       throw BuildError(format("invalid ownership on file '%1%'") % path);
+    }
     mode_t mode = st.st_mode & ~S_IFMT;
     assert(S_ISLNK(st.st_mode) ||
            (st.st_uid == geteuid() && (mode == 0444 || mode == 0555) &&
@@ -513,18 +539,20 @@ static void canonicalisePathMetaData_(const Path& path, uid_t fromUid,
      users group); we check for this case below. */
   if (st.st_uid != geteuid()) {
 #if HAVE_LCHOWN
-    if (lchown(path.c_str(), geteuid(), getegid()) == -1)
+    if (lchown(path.c_str(), geteuid(), getegid()) == -1) {
 #else
     if (!S_ISLNK(st.st_mode) && chown(path.c_str(), geteuid(), getegid()) == -1)
 #endif
       throw SysError(format("changing owner of '%1%' to %2%") % path %
                      geteuid());
+    }
   }
 
   if (S_ISDIR(st.st_mode)) {
     DirEntries entries = readDirectory(path);
-    for (auto& i : entries)
+    for (auto& i : entries) {
       canonicalisePathMetaData_(path + "/" + i.name, fromUid, inodesSeen);
+    }
   }
 }
 
@@ -535,8 +563,9 @@ void canonicalisePathMetaData(const Path& path, uid_t fromUid,
   /* On platforms that don't have lchown(), the top-level path can't
      be a symlink, since we can't change its ownership. */
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting attributes of path '%1%'") % path);
+  }
 
   if (st.st_uid != geteuid()) {
     assert(S_ISLNK(st.st_mode));
@@ -557,10 +586,11 @@ void LocalStore::checkDerivationOutputs(const Path& drvPath,
 
   if (drv.isFixedOutput()) {
     DerivationOutputs::const_iterator out = drv.outputs.find("out");
-    if (out == drv.outputs.end())
+    if (out == drv.outputs.end()) {
       throw Error(
           format("derivation '%1%' does not have an output named 'out'") %
           drvPath);
+    }
 
     bool recursive;
     Hash h;
@@ -569,11 +599,12 @@ void LocalStore::checkDerivationOutputs(const Path& drvPath,
 
     StringPairs::const_iterator j = drv.env.find("out");
     if (out->second.path != outPath || j == drv.env.end() ||
-        j->second != outPath)
+        j->second != outPath) {
       throw Error(
           format(
               "derivation '%1%' has incorrect output '%2%', should be '%3%'") %
           drvPath % out->second.path % outPath);
+    }
   }
 
   else {
@@ -589,21 +620,23 @@ void LocalStore::checkDerivationOutputs(const Path& drvPath,
       Path outPath = makeOutputPath(i.first, h, drvName);
       StringPairs::const_iterator j = drv.env.find(i.first);
       if (i.second.path != outPath || j == drv.env.end() ||
-          j->second != outPath)
+          j->second != outPath) {
         throw Error(format("derivation '%1%' has incorrect output '%2%', "
                            "should be '%3%'") %
                     drvPath % i.second.path % outPath);
+      }
     }
   }
 }
 
 uint64_t LocalStore::addValidPath(State& state, const ValidPathInfo& info,
                                   bool checkOutputs) {
-  if (info.ca != "" && !info.isContentAddressed(*this))
+  if (info.ca != "" && !info.isContentAddressed(*this)) {
     throw Error(
         "cannot add path '%s' to the Nix store because it claims to be "
         "content-addressed but isn't",
         info.path);
+  }
 
   state.stmtRegisterValidPath
       .use()(info.path)(info.narHash.to_string(Base16))(
@@ -697,8 +730,9 @@ void LocalStore::queryPathInfoUncached(
       /* Get the references. */
       auto useQueryReferences(state->stmtQueryReferences.use()(info->id));
 
-      while (useQueryReferences.next())
+      while (useQueryReferences.next()) {
         info->references.insert(useQueryReferences.getStr(0));
+      }
 
       return info;
     }));
@@ -740,10 +774,11 @@ bool LocalStore::isValidPathUncached(const Path& path) {
 PathSet LocalStore::queryValidPaths(const PathSet& paths,
                                     SubstituteFlag maybeSubstitute) {
   PathSet res;
-  for (auto& i : paths)
+  for (auto& i : paths) {
     if (isValidPath(i)) {
       res.insert(i);
     }
+  }
   return res;
 }
 
@@ -752,7 +787,9 @@ PathSet LocalStore::queryAllValidPaths() {
     auto state(_state.lock());
     auto use(state->stmtQueryValidPaths.use());
     PathSet res;
-    while (use.next()) res.insert(use.getStr(0));
+    while (use.next()) {
+      res.insert(use.getStr(0));
+    }
     return res;
   });
 }
@@ -761,8 +798,9 @@ void LocalStore::queryReferrers(State& state, const Path& path,
                                 PathSet& referrers) {
   auto useQueryReferrers(state.stmtQueryReferrers.use()(path));
 
-  while (useQueryReferrers.next())
+  while (useQueryReferrers.next()) {
     referrers.insert(useQueryReferrers.getStr(0));
+  }
 }
 
 void LocalStore::queryReferrers(const Path& path, PathSet& referrers) {
@@ -782,8 +820,9 @@ PathSet LocalStore::queryValidDerivers(const Path& path) {
     auto useQueryValidDerivers(state->stmtQueryValidDerivers.use()(path));
 
     PathSet derivers;
-    while (useQueryValidDerivers.next())
+    while (useQueryValidDerivers.next()) {
       derivers.insert(useQueryValidDerivers.getStr(1));
+    }
 
     return derivers;
   });
@@ -797,8 +836,9 @@ PathSet LocalStore::queryDerivationOutputs(const Path& path) {
         queryValidPathId(*state, path)));
 
     PathSet outputs;
-    while (useQueryDerivationOutputs.next())
+    while (useQueryDerivationOutputs.next()) {
       outputs.insert(useQueryDerivationOutputs.getStr(1));
+    }
 
     return outputs;
   });
@@ -812,8 +852,9 @@ StringSet LocalStore::queryDerivationOutputNames(const Path& path) {
         queryValidPathId(*state, path)));
 
     StringSet outputNames;
-    while (useQueryDerivationOutputs.next())
+    while (useQueryDerivationOutputs.next()) {
       outputNames.insert(useQueryDerivationOutputs.getStr(0));
+    }
 
     return outputNames;
   });
@@ -865,11 +906,13 @@ PathSet LocalStore::querySubstitutablePaths(const PathSet& paths) {
     auto valid = sub->queryValidPaths(remaining);
 
     PathSet remaining2;
-    for (auto& path : remaining)
-      if (valid.count(path))
+    for (auto& path : remaining) {
+      if (valid.count(path)) {
         res.insert(path);
-      else
+      } else {
         remaining2.insert(path);
+      }
+    }
 
     std::swap(remaining, remaining2);
   }
@@ -935,24 +978,26 @@ void LocalStore::registerValidPaths(const ValidPathInfos& infos) {
 
     for (auto& i : infos) {
       assert(i.narHash.type == htSHA256);
-      if (isValidPath_(*state, i.path))
+      if (isValidPath_(*state, i.path)) {
         updatePathInfo(*state, i);
-      else
+      } else {
         addValidPath(*state, i, false);
+      }
       paths.insert(i.path);
     }
 
     for (auto& i : infos) {
       auto referrer = queryValidPathId(*state, i.path);
-      for (auto& j : i.references)
+      for (auto& j : i.references) {
         state->stmtAddReference.use()(referrer)(queryValidPathId(*state, j))
             .exec();
+      }
     }
 
     /* Check that the derivation outputs are correct.  We can't do
        this in addValidPath() above, because the references might
        not be valid yet. */
-    for (auto& i : infos)
+    for (auto& i : infos) {
       if (isDerivation(i.path)) {
         // FIXME: inefficient; we already loaded the
         // derivation in addValidPath().
@@ -960,6 +1005,7 @@ void LocalStore::registerValidPaths(const ValidPathInfos& infos) {
             readDerivation(realStoreDir + "/" + baseNameOf(i.path));
         checkDerivationOutputs(i.path, drv);
       }
+    }
 
     /* Do a topological sort of the paths.  This will throw an
        error if a cycle is detected and roll back the
@@ -989,8 +1035,9 @@ void LocalStore::invalidatePath(State& state, const Path& path) {
 
 const PublicKeys& LocalStore::getPublicKeys() {
   auto state(_state.lock());
-  if (!state->publicKeys)
+  if (!state->publicKeys) {
     state->publicKeys = std::make_unique<PublicKeys>(getDefaultPublicKeys());
+  }
   return *state->publicKeys;
 }
 
@@ -1039,15 +1086,17 @@ void LocalStore::addToStore(const ValidPathInfo& info, Source& source,
 
       auto hashResult = hashSink.finish();
 
-      if (hashResult.first != info.narHash)
+      if (hashResult.first != info.narHash) {
         throw Error(
             "hash mismatch importing path '%s';\n  wanted: %s\n  got:    %s",
             info.path, info.narHash.to_string(), hashResult.first.to_string());
+      }
 
-      if (hashResult.second != info.narSize)
+      if (hashResult.second != info.narSize) {
         throw Error(
             "size mismatch importing path '%s';\n  wanted: %s\n  got:   %s",
             info.path, info.narSize, hashResult.second);
+      }
 
       autoGC();
 
@@ -1130,10 +1179,11 @@ Path LocalStore::addToStore(const string& name, const Path& _srcPath,
      method for very large paths, but `copyPath' is mainly used for
      small files. */
   StringSink sink;
-  if (recursive)
+  if (recursive) {
     dumpPath(srcPath, sink, filter);
-  else
+  } else {
     sink.s = make_ref<std::string>(readFile(srcPath));
+  }
 
   return addToStoreFromDump(*sink.s, name, recursive, hashAlgo, repair);
 }
@@ -1206,10 +1256,11 @@ void LocalStore::invalidatePathChecked(const Path& path) {
       PathSet referrers;
       queryReferrers(*state, path, referrers);
       referrers.erase(path); /* ignore self-references */
-      if (!referrers.empty())
+      if (!referrers.empty()) {
         throw PathInUse(
             format("cannot delete path '%1%' because it is in use by %2%") %
             path % showPaths(referrers));
+      }
       invalidatePath(*state, path);
     }
 
@@ -1238,8 +1289,9 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair) {
 
   fdGCLock = -1;
 
-  for (auto& i : validPaths2)
+  for (auto& i : validPaths2) {
     verifyPath(i, store, done, validPaths, repair, errors);
+  }
 
   /* Optionally, check the content hashes (slow). */
   if (checkContents) {
@@ -1328,13 +1380,14 @@ void LocalStore::verifyPath(const Path& path, const PathSet& store,
     bool canInvalidate = true;
     PathSet referrers;
     queryReferrers(path, referrers);
-    for (auto& i : referrers)
+    for (auto& i : referrers) {
       if (i != path) {
         verifyPath(i, store, done, validPaths, repair, errors);
         if (validPaths.find(i) != validPaths.end()) {
           canInvalidate = false;
         }
       }
+    }
 
     if (canInvalidate) {
       LOG(WARNING) << "path '" << path
@@ -1463,10 +1516,12 @@ void LocalStore::createUser(const std::string& userName, uid_t userId) {
   for (auto& dir : {fmt("%s/profiles/per-user/%s", stateDir, userName),
                     fmt("%s/gcroots/per-user/%s", stateDir, userName)}) {
     createDirs(dir);
-    if (chmod(dir.c_str(), 0755) == -1)
+    if (chmod(dir.c_str(), 0755) == -1) {
       throw SysError("changing permissions of directory '%s'", dir);
-    if (chown(dir.c_str(), userId, getgid()) == -1)
+    }
+    if (chown(dir.c_str(), userId, getgid()) == -1) {
       throw SysError("changing owner of directory '%s'", dir);
+    }
   }
 }
 
diff --git a/third_party/nix/src/libstore/misc.cc b/third_party/nix/src/libstore/misc.cc
index daed88cdc9..a82fc1251c 100644
--- a/third_party/nix/src/libstore/misc.cc
+++ b/third_party/nix/src/libstore/misc.cc
@@ -47,35 +47,44 @@ void Store::computeFSClosure(const PathSet& startPaths, PathSet& paths_,
             if (flipDirection) {
               PathSet referrers;
               queryReferrers(path, referrers);
-              for (auto& ref : referrers)
+              for (auto& ref : referrers) {
                 if (ref != path) {
                   enqueue(ref);
                 }
+              }
 
-              if (includeOutputs)
+              if (includeOutputs) {
                 for (auto& i : queryValidDerivers(path)) {
                   enqueue(i);
                 }
+              }
 
-              if (includeDerivers && isDerivation(path))
-                for (auto& i : queryDerivationOutputs(path))
-                  if (isValidPath(i) && queryPathInfo(i)->deriver == path)
+              if (includeDerivers && isDerivation(path)) {
+                for (auto& i : queryDerivationOutputs(path)) {
+                  if (isValidPath(i) && queryPathInfo(i)->deriver == path) {
                     enqueue(i);
+                  }
+                }
+              }
 
             } else {
-              for (auto& ref : info->references)
+              for (auto& ref : info->references) {
                 if (ref != path) {
                   enqueue(ref);
                 }
+              }
 
-              if (includeOutputs && isDerivation(path))
-                for (auto& i : queryDerivationOutputs(path))
+              if (includeOutputs && isDerivation(path)) {
+                for (auto& i : queryDerivationOutputs(path)) {
                   if (isValidPath(i)) {
                     enqueue(i);
                   }
+                }
+              }
 
-              if (includeDerivers && isValidPath(info->deriver))
+              if (includeDerivers && isValidPath(info->deriver)) {
                 enqueue(info->deriver);
+              }
             }
 
             {
@@ -105,7 +114,9 @@ void Store::computeFSClosure(const PathSet& startPaths, PathSet& paths_,
 
   {
     auto state(state_.lock());
-    while (state->pending) state.wait(done);
+    while (state->pending) {
+      state.wait(done);
+    }
     if (state->exc) {
       std::rethrow_exception(state->exc);
     }
@@ -154,9 +165,10 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
       state->willBuild.insert(drvPath);
     }
 
-    for (auto& i : drv.inputDrvs)
+    for (auto& i : drv.inputDrvs) {
       pool.enqueue(
           std::bind(doPath, makeDrvPathWithOutputs(i.first, i.second)));
+    }
   };
 
   auto checkOutput = [&](const Path& drvPath, ref<Derivation> drv,
@@ -181,8 +193,9 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
         drvState->left--;
         drvState->outPaths.insert(outPath);
         if (!drvState->left) {
-          for (auto& path : drvState->outPaths)
+          for (auto& path : drvState->outPaths) {
             pool.enqueue(std::bind(doPath, path));
+          }
         }
       }
     }
@@ -211,20 +224,24 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
       ParsedDerivation parsedDrv(i2.first, drv);
 
       PathSet invalid;
-      for (auto& j : drv.outputs)
-        if (wantOutput(j.first, i2.second) && !isValidPath(j.second.path))
+      for (auto& j : drv.outputs) {
+        if (wantOutput(j.first, i2.second) && !isValidPath(j.second.path)) {
           invalid.insert(j.second.path);
+        }
+      }
       if (invalid.empty()) {
         return;
       }
 
       if (settings.useSubstitutes && parsedDrv.substitutesAllowed()) {
         auto drvState = make_ref<Sync<DrvState>>(DrvState(invalid.size()));
-        for (auto& output : invalid)
+        for (auto& output : invalid) {
           pool.enqueue(std::bind(checkOutput, i2.first,
                                  make_ref<Derivation>(drv), output, drvState));
-      } else
+        }
+      } else {
         mustBuildDrv(i2.first, drv);
+      }
 
     } else {
       if (isValidPath(path)) {
@@ -250,8 +267,9 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
         state->narSize += info->second.narSize;
       }
 
-      for (auto& ref : info->second.references)
+      for (auto& ref : info->second.references) {
         pool.enqueue(std::bind(doPath, ref));
+      }
     }
   };
 
@@ -269,10 +287,11 @@ Paths Store::topoSortPaths(const PathSet& paths) {
   std::function<void(const Path& path, const Path* parent)> dfsVisit;
 
   dfsVisit = [&](const Path& path, const Path* parent) {
-    if (parents.find(path) != parents.end())
+    if (parents.find(path) != parents.end()) {
       throw BuildError(
           format("cycle detected in the references of '%1%' from '%2%'") %
           path % *parent);
+    }
 
     if (visited.find(path) != visited.end()) {
       return;
@@ -286,12 +305,13 @@ Paths Store::topoSortPaths(const PathSet& paths) {
     } catch (InvalidPath&) {
     }
 
-    for (auto& i : references)
+    for (auto& i : references) {
       /* Don't traverse into paths that don't exist.  That can
          happen due to substitutes for non-existent paths. */
       if (i != path && paths.find(i) != paths.end()) {
         dfsVisit(i, &path);
       }
+    }
 
     sorted.push_front(path);
     parents.erase(path);
diff --git a/third_party/nix/src/libstore/nar-accessor.cc b/third_party/nix/src/libstore/nar-accessor.cc
index 8a57179ab3..8be22ada2e 100644
--- a/third_party/nix/src/libstore/nar-accessor.cc
+++ b/third_party/nix/src/libstore/nar-accessor.cc
@@ -45,14 +45,17 @@ struct NarAccessor : public FSAccessor {
 
     void createMember(const Path& path, NarMember member) {
       size_t level = std::count(path.begin(), path.end(), '/');
-      while (parents.size() > level) parents.pop();
+      while (parents.size() > level) {
+        parents.pop();
+      }
 
       if (parents.empty()) {
         acc.root = std::move(member);
         parents.push(&acc.root);
       } else {
-        if (parents.top()->type != FSAccessor::Type::tDirectory)
+        if (parents.top()->type != FSAccessor::Type::tDirectory) {
           throw Error("NAR file missing parent directory of path '%s'", path);
+        }
         auto result = parents.top()->children.emplace(baseNameOf(path),
                                                       std::move(member));
         parents.push(&result.first->second);
@@ -118,8 +121,9 @@ struct NarAccessor : public FSAccessor {
       } else if (type == "symlink") {
         member.type = FSAccessor::Type::tSymlink;
         member.target = v.value("target", "");
-      } else
+      } else {
         return;
+      }
     };
 
     json v = json::parse(listing);
@@ -157,8 +161,9 @@ struct NarAccessor : public FSAccessor {
 
   NarMember& get(const Path& path) {
     auto result = find(path);
-    if (result == nullptr)
+    if (result == nullptr) {
       throw Error("NAR file does not contain path '%1%'", path);
+    }
     return *result;
   }
 
@@ -173,9 +178,10 @@ struct NarAccessor : public FSAccessor {
   StringSet readDirectory(const Path& path) override {
     auto i = get(path);
 
-    if (i.type != FSAccessor::Type::tDirectory)
+    if (i.type != FSAccessor::Type::tDirectory) {
       throw Error(format("path '%1%' inside NAR file is not a directory") %
                   path);
+    }
 
     StringSet res;
     for (auto& child : i.children) {
@@ -187,9 +193,10 @@ struct NarAccessor : public FSAccessor {
 
   std::string readFile(const Path& path) override {
     auto i = get(path);
-    if (i.type != FSAccessor::Type::tRegular)
+    if (i.type != FSAccessor::Type::tRegular) {
       throw Error(format("path '%1%' inside NAR file is not a regular file") %
                   path);
+    }
 
     if (getNarBytes) {
       return getNarBytes(i.start, i.size);
@@ -201,8 +208,9 @@ struct NarAccessor : public FSAccessor {
 
   std::string readLink(const Path& path) override {
     auto i = get(path);
-    if (i.type != FSAccessor::Type::tSymlink)
+    if (i.type != FSAccessor::Type::tSymlink) {
       throw Error(format("path '%1%' inside NAR file is not a symlink") % path);
+    }
     return i.target;
   }
 };
@@ -241,8 +249,9 @@ void listNar(JSONPlaceholder& res, ref<FSAccessor> accessor, const Path& path,
           if (recurse) {
             auto res3 = res2.placeholder(name);
             listNar(res3, accessor, path + "/" + name, true);
-          } else
+          } else {
             res2.object(name);
+          }
         }
       }
       break;
diff --git a/third_party/nix/src/libstore/nar-info-disk-cache.cc b/third_party/nix/src/libstore/nar-info-disk-cache.cc
index 6d9aeb129d..3adda508d0 100644
--- a/third_party/nix/src/libstore/nar-info-disk-cache.cc
+++ b/third_party/nix/src/libstore/nar-info-disk-cache.cc
@@ -76,8 +76,9 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache {
 
     state->db = SQLite(dbPath);
 
-    if (sqlite3_busy_timeout(state->db, 60 * 60 * 1000) != SQLITE_OK)
+    if (sqlite3_busy_timeout(state->db, 60 * 60 * 1000) != SQLITE_OK) {
       throwSQLiteError(state->db, "setting timeout");
+    }
 
     // We can always reproduce the cache.
     state->db.exec("pragma synchronous = off");
@@ -224,12 +225,15 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache {
           narInfo->fileSize = queryNAR.getInt(5);
           narInfo->narHash = Hash(queryNAR.getStr(6));
           narInfo->narSize = queryNAR.getInt(7);
-          for (auto& r : tokenizeString<Strings>(queryNAR.getStr(8), " "))
+          for (auto& r : tokenizeString<Strings>(queryNAR.getStr(8), " ")) {
             narInfo->references.insert(cache.storeDir + "/" + r);
-          if (!queryNAR.isNull(9))
+          }
+          if (!queryNAR.isNull(9)) {
             narInfo->deriver = cache.storeDir + "/" + queryNAR.getStr(9);
-          for (auto& sig : tokenizeString<Strings>(queryNAR.getStr(10), " "))
+          }
+          for (auto& sig : tokenizeString<Strings>(queryNAR.getStr(10), " ")) {
             narInfo->sigs.insert(sig);
+          }
           narInfo->ca = queryNAR.getStr(11);
 
           return {oValid, narInfo};
diff --git a/third_party/nix/src/libstore/nar-info.cc b/third_party/nix/src/libstore/nar-info.cc
index fa7d72c8ae..fee470fc7d 100644
--- a/third_party/nix/src/libstore/nar-info.cc
+++ b/third_party/nix/src/libstore/nar-info.cc
@@ -40,19 +40,19 @@ NarInfo::NarInfo(const Store& store, const std::string& s,
         corrupt();
       }
       path = value;
-    } else if (name == "URL")
+    } else if (name == "URL") {
       url = value;
-    else if (name == "Compression")
+    } else if (name == "Compression") {
       compression = value;
-    else if (name == "FileHash")
+    } else if (name == "FileHash") {
       fileHash = parseHashField(value);
-    else if (name == "FileSize") {
+    } else if (name == "FileSize") {
       if (!string2Int(value, fileSize)) {
         corrupt();
       }
-    } else if (name == "NarHash")
+    } else if (name == "NarHash") {
       narHash = parseHashField(value);
-    else if (name == "NarSize") {
+    } else if (name == "NarSize") {
       if (!string2Int(value, narSize)) {
         corrupt();
       }
@@ -76,11 +76,11 @@ NarInfo::NarInfo(const Store& store, const std::string& s,
         }
         deriver = p;
       }
-    } else if (name == "System")
+    } else if (name == "System") {
       system = value;
-    else if (name == "Sig")
+    } else if (name == "Sig") {
       sigs.insert(value);
-    else if (name == "CA") {
+    } else if (name == "CA") {
       if (!ca.empty()) {
         corrupt();
       }
diff --git a/third_party/nix/src/libstore/optimise-store.cc b/third_party/nix/src/libstore/optimise-store.cc
index ad37190236..8c0f24d382 100644
--- a/third_party/nix/src/libstore/optimise-store.cc
+++ b/third_party/nix/src/libstore/optimise-store.cc
@@ -17,10 +17,12 @@ namespace nix {
 
 static void makeWritable(const Path& path) {
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting attributes of path '%1%'") % path);
-  if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
+  }
+  if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1) {
     throw SysError(format("changing writability of '%1%'") % path);
+  }
 }
 
 struct MakeReadOnly {
@@ -98,8 +100,9 @@ void LocalStore::optimisePath_(OptimiseStats& stats, const Path& path,
   checkInterrupt();
 
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting attributes of path '%1%'") % path);
+  }
 
 #if __APPLE__
   /* HFS/macOS has some undocumented security feature disabling hardlinking for
@@ -192,8 +195,9 @@ retry:
   /* Yes!  We've seen a file with the same contents.  Replace the
      current file with a hard link to that file. */
   struct stat stLink;
-  if (lstat(linkPath.c_str(), &stLink))
+  if (lstat(linkPath.c_str(), &stLink)) {
     throw SysError(format("getting attributes of path '%1%'") % linkPath);
+  }
 
   if (st.st_ino == stLink.st_ino) {
     DLOG(INFO) << path << " is already linked to " << linkPath;
diff --git a/third_party/nix/src/libstore/parsed-derivations.cc b/third_party/nix/src/libstore/parsed-derivations.cc
index 29133664fd..72ed36d32d 100644
--- a/third_party/nix/src/libstore/parsed-derivations.cc
+++ b/third_party/nix/src/libstore/parsed-derivations.cc
@@ -20,40 +20,44 @@ std::optional<std::string> ParsedDerivation::getStringAttr(
     const std::string& name) const {
   if (structuredAttrs) {
     auto i = structuredAttrs->find(name);
-    if (i == structuredAttrs->end())
+    if (i == structuredAttrs->end()) {
       return {};
-    else {
-      if (!i->is_string())
+    } else {
+      if (!i->is_string()) {
         throw Error("attribute '%s' of derivation '%s' must be a string", name,
                     drvPath);
+      }
       return i->get<std::string>();
     }
   } else {
     auto i = drv.env.find(name);
-    if (i == drv.env.end())
+    if (i == drv.env.end()) {
       return {};
-    else
+    } else {
       return i->second;
+    }
   }
 }
 
 bool ParsedDerivation::getBoolAttr(const std::string& name, bool def) const {
   if (structuredAttrs) {
     auto i = structuredAttrs->find(name);
-    if (i == structuredAttrs->end())
+    if (i == structuredAttrs->end()) {
       return def;
-    else {
-      if (!i->is_boolean())
+    } else {
+      if (!i->is_boolean()) {
         throw Error("attribute '%s' of derivation '%s' must be a Boolean", name,
                     drvPath);
+      }
       return i->get<bool>();
     }
   } else {
     auto i = drv.env.find(name);
-    if (i == drv.env.end())
+    if (i == drv.env.end()) {
       return def;
-    else
+    } else {
       return i->second == "1";
+    }
   }
 }
 
@@ -61,48 +65,54 @@ std::optional<Strings> ParsedDerivation::getStringsAttr(
     const std::string& name) const {
   if (structuredAttrs) {
     auto i = structuredAttrs->find(name);
-    if (i == structuredAttrs->end())
+    if (i == structuredAttrs->end()) {
       return {};
-    else {
-      if (!i->is_array())
+    } else {
+      if (!i->is_array()) {
         throw Error(
             "attribute '%s' of derivation '%s' must be a list of strings", name,
             drvPath);
+      }
       Strings res;
       for (auto j = i->begin(); j != i->end(); ++j) {
-        if (!j->is_string())
+        if (!j->is_string()) {
           throw Error(
               "attribute '%s' of derivation '%s' must be a list of strings",
               name, drvPath);
+        }
         res.push_back(j->get<std::string>());
       }
       return res;
     }
   } else {
     auto i = drv.env.find(name);
-    if (i == drv.env.end())
+    if (i == drv.env.end()) {
       return {};
-    else
+    } else {
       return tokenizeString<Strings>(i->second);
+    }
   }
 }
 
 StringSet ParsedDerivation::getRequiredSystemFeatures() const {
   StringSet res;
-  for (auto& i : getStringsAttr("requiredSystemFeatures").value_or(Strings()))
+  for (auto& i : getStringsAttr("requiredSystemFeatures").value_or(Strings())) {
     res.insert(i);
+  }
   return res;
 }
 
 bool ParsedDerivation::canBuildLocally() const {
   if (drv.platform != settings.thisSystem.get() &&
-      !settings.extraPlatforms.get().count(drv.platform) && !drv.isBuiltin())
+      !settings.extraPlatforms.get().count(drv.platform) && !drv.isBuiltin()) {
     return false;
+  }
 
-  for (auto& feature : getRequiredSystemFeatures())
+  for (auto& feature : getRequiredSystemFeatures()) {
     if (!settings.systemFeatures.get().count(feature)) {
       return false;
     }
+  }
 
   return true;
 }
diff --git a/third_party/nix/src/libstore/pathlocks.cc b/third_party/nix/src/libstore/pathlocks.cc
index ffec3d7d7e..a0d7b721ec 100644
--- a/third_party/nix/src/libstore/pathlocks.cc
+++ b/third_party/nix/src/libstore/pathlocks.cc
@@ -18,8 +18,9 @@ AutoCloseFD openLockFile(const Path& path, bool create) {
   AutoCloseFD fd;
 
   fd = open(path.c_str(), O_CLOEXEC | O_RDWR | (create ? O_CREAT : 0), 0600);
-  if (!fd && (create || errno != ENOENT))
+  if (!fd && (create || errno != ENOENT)) {
     throw SysError(format("opening lock file '%1%'") % path);
+  }
 
   return fd;
 }
@@ -37,22 +38,24 @@ void deleteLockFile(const Path& path, int fd) {
 
 bool lockFile(int fd, LockType lockType, bool wait) {
   int type;
-  if (lockType == ltRead)
+  if (lockType == ltRead) {
     type = LOCK_SH;
-  else if (lockType == ltWrite)
+  } else if (lockType == ltWrite) {
     type = LOCK_EX;
-  else if (lockType == ltNone)
+  } else if (lockType == ltNone) {
     type = LOCK_UN;
-  else
+  } else {
     abort();
+  }
 
   if (wait) {
     while (flock(fd, type) != 0) {
       checkInterrupt();
-      if (errno != EINTR)
+      if (errno != EINTR) {
         throw SysError(format("acquiring/releasing lock"));
-      else
+      } else {
         return false;
+      }
     }
   } else {
     while (flock(fd, type | LOCK_NB) != 0) {
@@ -118,16 +121,18 @@ bool PathLocks::lockPaths(const PathSet& paths, const string& waitMsg,
       /* Check that the lock file hasn't become stale (i.e.,
          hasn't been unlinked). */
       struct stat st;
-      if (fstat(fd.get(), &st) == -1)
+      if (fstat(fd.get(), &st) == -1) {
         throw SysError(format("statting lock file '%1%'") % lockPath);
-      if (st.st_size != 0)
+      }
+      if (st.st_size != 0) {
         /* This lock file has been unlinked, so we're holding
            a lock on a deleted file.  This means that other
            processes may create and acquire a lock on
            `lockPath', and proceed.  So we must retry. */
         DLOG(INFO) << "open lock file '" << lockPath << "' has become stale";
-      else
+      } else {
         break;
+      }
     }
 
     /* Use borrow so that the descriptor isn't closed. */
diff --git a/third_party/nix/src/libstore/profiles.cc b/third_party/nix/src/libstore/profiles.cc
index 38d0972e44..38ad0c01e4 100644
--- a/third_party/nix/src/libstore/profiles.cc
+++ b/third_party/nix/src/libstore/profiles.cc
@@ -28,10 +28,11 @@ static int parseName(const string& profileName, const string& name) {
     return -1;
   }
   int n;
-  if (string2Int(string(s, 0, p), n) && n >= 0)
+  if (string2Int(string(s, 0, p), n) && n >= 0) {
     return n;
-  else
+  } else {
     return -1;
+  }
 }
 
 Generations findGenerations(Path profile, int& curGen) {
@@ -47,8 +48,9 @@ Generations findGenerations(Path profile, int& curGen) {
       gen.path = profileDir + "/" + i.name;
       gen.number = n;
       struct stat st;
-      if (lstat(gen.path.c_str(), &st) != 0)
+      if (lstat(gen.path.c_str(), &st) != 0) {
         throw SysError(format("statting '%1%'") % gen.path);
+      }
       gen.creationTime = st.st_mtime;
       gens.push_back(gen);
     }
@@ -105,8 +107,9 @@ Path createGeneration(ref<LocalFSStore> store, Path profile, Path outPath) {
 }
 
 static void removeFile(const Path& path) {
-  if (remove(path.c_str()) == -1)
+  if (remove(path.c_str()) == -1) {
     throw SysError(format("cannot unlink '%1%'") % path);
+  }
 }
 
 void deleteGeneration(const Path& profile, unsigned int gen) {
@@ -134,9 +137,10 @@ void deleteGenerations(const Path& profile,
   int curGen;
   Generations gens = findGenerations(profile, curGen);
 
-  if (gensToDelete.find(curGen) != gensToDelete.end())
+  if (gensToDelete.find(curGen) != gensToDelete.end()) {
     throw Error(format("cannot delete current generation of profile %1%'") %
                 profile);
+  }
 
   for (auto& i : gens) {
     if (gensToDelete.find(i.number) == gensToDelete.end()) {
@@ -176,10 +180,11 @@ void deleteOldGenerations(const Path& profile, bool dryRun) {
   int curGen;
   Generations gens = findGenerations(profile, curGen);
 
-  for (auto& i : gens)
+  for (auto& i : gens) {
     if (i.number != curGen) {
       deleteGeneration2(profile, i.number, dryRun);
     }
+  }
 }
 
 void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun) {
@@ -190,7 +195,7 @@ void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun) {
   Generations gens = findGenerations(profile, curGen);
 
   bool canDelete = false;
-  for (auto i = gens.rbegin(); i != gens.rend(); ++i)
+  for (auto i = gens.rbegin(); i != gens.rend(); ++i) {
     if (canDelete) {
       assert(i->creationTime < t);
       if (i->number != curGen) {
@@ -203,6 +208,7 @@ void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun) {
          time. */
       canDelete = true;
     }
+  }
 }
 
 void deleteGenerationsOlderThan(const Path& profile, const string& timeSpec,
@@ -211,8 +217,9 @@ void deleteGenerationsOlderThan(const Path& profile, const string& timeSpec,
   string strDays = string(timeSpec, 0, timeSpec.size() - 1);
   int days;
 
-  if (!string2Int(strDays, days) || days < 1)
+  if (!string2Int(strDays, days) || days < 1) {
     throw Error(format("invalid number of days specifier '%1%'") % timeSpec);
+  }
 
   time_t oldTime = curTime - days * 24 * 3600;
 
diff --git a/third_party/nix/src/libstore/references.cc b/third_party/nix/src/libstore/references.cc
index a46bdc758f..64b997ce3e 100644
--- a/third_party/nix/src/libstore/references.cc
+++ b/third_party/nix/src/libstore/references.cc
@@ -21,20 +21,22 @@ static void search(const unsigned char* s, size_t len, StringSet& hashes,
     for (unsigned int i = 0; i < 256; ++i) {
       isBase32[i] = false;
     }
-    for (unsigned int i = 0; i < base32Chars.size(); ++i)
+    for (unsigned int i = 0; i < base32Chars.size(); ++i) {
       isBase32[(unsigned char)base32Chars[i]] = true;
+    }
     initialised = true;
   }
 
   for (size_t i = 0; i + refLength <= len;) {
     int j;
     bool match = true;
-    for (j = refLength - 1; j >= 0; --j)
+    for (j = refLength - 1; j >= 0; --j) {
       if (!isBase32[(unsigned char)s[i + j]]) {
         i += j + 1;
         match = false;
         break;
       }
+    }
     if (!match) {
       continue;
     }
diff --git a/third_party/nix/src/libstore/remote-fs-accessor.cc b/third_party/nix/src/libstore/remote-fs-accessor.cc
index 0b9bb805eb..819f54c161 100644
--- a/third_party/nix/src/libstore/remote-fs-accessor.cc
+++ b/third_party/nix/src/libstore/remote-fs-accessor.cc
@@ -48,9 +48,10 @@ std::pair<ref<FSAccessor>, Path> RemoteFSAccessor::fetch(const Path& path_) {
   auto storePath = store->toStorePath(path);
   std::string restPath = std::string(path, storePath.size());
 
-  if (!store->isValidPath(storePath))
+  if (!store->isValidPath(storePath)) {
     throw InvalidPath(format("path '%1%' is not a valid store path") %
                       storePath);
+  }
 
   auto i = nars.find(storePath);
   if (i != nars.end()) {
@@ -73,8 +74,9 @@ std::pair<ref<FSAccessor>, Path> RemoteFSAccessor::fetch(const Path& path_) {
               throw SysError("opening NAR cache file '%s'", cacheFile);
             }
 
-            if (lseek(fd.get(), offset, SEEK_SET) != (off_t)offset)
+            if (lseek(fd.get(), offset, SEEK_SET) != (off_t)offset) {
               throw SysError("seeking in '%s'", cacheFile);
+            }
 
             std::string buf(length, 0);
             readFull(fd.get(), (unsigned char*)buf.data(), length);
diff --git a/third_party/nix/src/libstore/remote-store.cc b/third_party/nix/src/libstore/remote-store.cc
index e6849cb160..b0025df98f 100644
--- a/third_party/nix/src/libstore/remote-store.cc
+++ b/third_party/nix/src/libstore/remote-store.cc
@@ -57,9 +57,10 @@ RemoteStore::RemoteStore(const Params& params)
           })) {}
 
 ref<RemoteStore::Connection> RemoteStore::openConnectionWrapper() {
-  if (failed)
+  if (failed) {
     throw Error("opening a connection to remote store '%s' previously failed",
                 getUri());
+  }
   try {
     return openConnection();
   } catch (...) {
@@ -105,12 +106,14 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection() {
 
   struct sockaddr_un addr;
   addr.sun_family = AF_UNIX;
-  if (socketPath.size() + 1 >= sizeof(addr.sun_path))
+  if (socketPath.size() + 1 >= sizeof(addr.sun_path)) {
     throw Error(format("socket path '%1%' is too long") % socketPath);
+  }
   strcpy(addr.sun_path, socketPath.c_str());
 
-  if (::connect(conn->fd.get(), (struct sockaddr*)&addr, sizeof(addr)) == -1)
+  if (::connect(conn->fd.get(), (struct sockaddr*)&addr, sizeof(addr)) == -1) {
     throw SysError(format("cannot connect to daemon at '%1%'") % socketPath);
+  }
 
   conn->from.fd = conn->fd.get();
   conn->to.fd = conn->fd.get();
@@ -134,18 +137,21 @@ void RemoteStore::initConnection(Connection& conn) {
 
     conn.from >> conn.daemonVersion;
     if (GET_PROTOCOL_MAJOR(conn.daemonVersion) !=
-        GET_PROTOCOL_MAJOR(PROTOCOL_VERSION))
+        GET_PROTOCOL_MAJOR(PROTOCOL_VERSION)) {
       throw Error("Nix daemon protocol version not supported");
-    if (GET_PROTOCOL_MINOR(conn.daemonVersion) < 10)
+    }
+    if (GET_PROTOCOL_MINOR(conn.daemonVersion) < 10) {
       throw Error("the Nix daemon version is too old");
+    }
     conn.to << PROTOCOL_VERSION;
 
     if (GET_PROTOCOL_MINOR(conn.daemonVersion) >= 14) {
       int cpu = sameMachine() && settings.lockCPU ? lockToCurrentCPU() : -1;
-      if (cpu != -1)
+      if (cpu != -1) {
         conn.to << 1 << cpu;
-      else
+      } else {
         conn.to << 0;
+      }
     }
 
     if (GET_PROTOCOL_MINOR(conn.daemonVersion) >= 11) {
@@ -249,10 +255,11 @@ PathSet RemoteStore::queryValidPaths(const PathSet& paths,
   auto conn(getConnection());
   if (GET_PROTOCOL_MINOR(conn->daemonVersion) < 12) {
     PathSet res;
-    for (auto& i : paths)
+    for (auto& i : paths) {
       if (isValidPath(i)) {
         res.insert(i);
       }
+    }
     return res;
   } else {
     conn->to << wopQueryValidPaths << paths;
@@ -344,8 +351,9 @@ void RemoteStore::queryPathInfoUncached(
         conn.processStderr();
       } catch (Error& e) {
         // Ugly backwards compatibility hack.
-        if (e.msg().find("is not valid") != std::string::npos)
+        if (e.msg().find("is not valid") != std::string::npos) {
           throw InvalidPath(e.what());
+        }
         throw;
       }
       if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 17) {
@@ -456,9 +464,10 @@ void RemoteStore::addToStore(const ValidPathInfo& info, Source& source,
 Path RemoteStore::addToStore(const string& name, const Path& _srcPath,
                              bool recursive, HashType hashAlgo,
                              PathFilter& filter, RepairFlag repair) {
-  if (repair)
+  if (repair) {
     throw Error(
         "repairing is not supported when building through the Nix daemon");
+  }
 
   auto conn(getConnection());
 
@@ -483,10 +492,12 @@ Path RemoteStore::addToStore(const string& name, const Path& _srcPath,
   } catch (SysError& e) {
     /* Daemon closed while we were sending the path. Probably OOM
        or I/O error. */
-    if (e.errNo == EPIPE) try {
+    if (e.errNo == EPIPE) {
+      try {
         conn.processStderr();
       } catch (EndOfFile& e) {
       }
+    }
     throw;
   }
 
@@ -495,9 +506,10 @@ Path RemoteStore::addToStore(const string& name, const Path& _srcPath,
 
 Path RemoteStore::addTextToStore(const string& name, const string& s,
                                  const PathSet& references, RepairFlag repair) {
-  if (repair)
+  if (repair) {
     throw Error(
         "repairing is not supported when building through the Nix daemon");
+  }
 
   auto conn(getConnection());
   conn->to << wopAddTextToStore << name << s << references;
@@ -511,15 +523,16 @@ void RemoteStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
   conn->to << wopBuildPaths;
   if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 13) {
     conn->to << drvPaths;
-    if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 15)
+    if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 15) {
       conn->to << buildMode;
-    else
+    } else
         /* Old daemons did not take a 'buildMode' parameter, so we
            need to validate it here on the client side.  */
-        if (buildMode != bmNormal)
+        if (buildMode != bmNormal) {
       throw Error(
           "repairing or checking is not supported when building through the "
           "Nix daemon");
+    }
   } else {
     /* For backwards compatibility with old daemons, strip output
        identifiers. */
diff --git a/third_party/nix/src/libstore/sqlite.cc b/third_party/nix/src/libstore/sqlite.cc
index 5aa661afe0..f2650ed753 100644
--- a/third_party/nix/src/libstore/sqlite.cc
+++ b/third_party/nix/src/libstore/sqlite.cc
@@ -31,8 +31,9 @@ namespace nix {
 SQLite::SQLite(const Path& path) {
   if (sqlite3_open_v2(path.c_str(), &db,
                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
-                      0) != SQLITE_OK)
+                      0) != SQLITE_OK) {
     throw Error(format("cannot open SQLite database '%s'") % path);
+  }
 }
 
 SQLite::~SQLite() {
@@ -47,24 +48,27 @@ SQLite::~SQLite() {
 
 void SQLite::exec(const std::string& stmt) {
   retrySQLite<void>([&]() {
-    if (sqlite3_exec(db, stmt.c_str(), 0, 0, 0) != SQLITE_OK)
+    if (sqlite3_exec(db, stmt.c_str(), 0, 0, 0) != SQLITE_OK) {
       throwSQLiteError(db, format("executing SQLite statement '%s'") % stmt);
+    }
   });
 }
 
 void SQLiteStmt::create(sqlite3* db, const string& sql) {
   checkInterrupt();
   assert(!stmt);
-  if (sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, 0) != SQLITE_OK)
+  if (sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, 0) != SQLITE_OK) {
     throwSQLiteError(db, fmt("creating statement '%s'", sql));
+  }
   this->db = db;
   this->sql = sql;
 }
 
 SQLiteStmt::~SQLiteStmt() {
   try {
-    if (stmt && sqlite3_finalize(stmt) != SQLITE_OK)
+    if (stmt && sqlite3_finalize(stmt) != SQLITE_OK) {
       throwSQLiteError(db, fmt("finalizing statement '%s'", sql));
+    }
   } catch (...) {
     ignoreException();
   }
@@ -83,8 +87,9 @@ SQLiteStmt::Use& SQLiteStmt::Use::operator()(const std::string& value,
                                              bool notNull) {
   if (notNull) {
     if (sqlite3_bind_text(stmt, curArg++, value.c_str(), -1,
-                          SQLITE_TRANSIENT) != SQLITE_OK)
+                          SQLITE_TRANSIENT) != SQLITE_OK) {
       throwSQLiteError(stmt.db, "binding argument");
+    }
   } else {
     bind();
   }
@@ -93,8 +98,9 @@ SQLiteStmt::Use& SQLiteStmt::Use::operator()(const std::string& value,
 
 SQLiteStmt::Use& SQLiteStmt::Use::operator()(int64_t value, bool notNull) {
   if (notNull) {
-    if (sqlite3_bind_int64(stmt, curArg++, value) != SQLITE_OK)
+    if (sqlite3_bind_int64(stmt, curArg++, value) != SQLITE_OK) {
       throwSQLiteError(stmt.db, "binding argument");
+    }
   } else {
     bind();
   }
@@ -113,14 +119,16 @@ int SQLiteStmt::Use::step() { return sqlite3_step(stmt); }
 void SQLiteStmt::Use::exec() {
   int r = step();
   assert(r != SQLITE_ROW);
-  if (r != SQLITE_DONE)
+  if (r != SQLITE_DONE) {
     throwSQLiteError(stmt.db, fmt("executing SQLite statement '%s'", stmt.sql));
+  }
 }
 
 bool SQLiteStmt::Use::next() {
   int r = step();
-  if (r != SQLITE_DONE && r != SQLITE_ROW)
+  if (r != SQLITE_DONE && r != SQLITE_ROW) {
     throwSQLiteError(stmt.db, fmt("executing SQLite query '%s'", stmt.sql));
+  }
   return r == SQLITE_ROW;
 }
 
diff --git a/third_party/nix/src/libstore/ssh.cc b/third_party/nix/src/libstore/ssh.cc
index 20add33c00..1783732a1d 100644
--- a/third_party/nix/src/libstore/ssh.cc
+++ b/third_party/nix/src/libstore/ssh.cc
@@ -10,13 +10,15 @@ SSHMaster::SSHMaster(const std::string& host, const std::string& keyFile,
       useMaster(useMaster && !fakeSSH),
       compress(compress),
       logFD(logFD) {
-  if (host == "" || hasPrefix(host, "-"))
+  if (host == "" || hasPrefix(host, "-")) {
     throw Error("invalid SSH host name '%s'", host);
+  }
 }
 
 void SSHMaster::addCommonSSHOpts(Strings& args) {
-  for (auto& i : tokenizeString<Strings>(getEnv("NIX_SSHOPTS")))
+  for (auto& i : tokenizeString<Strings>(getEnv("NIX_SSHOPTS"))) {
     args.push_back(i);
+  }
   if (!keyFile.empty()) {
     args.insert(args.end(), {"-i", keyFile});
   }
@@ -44,12 +46,15 @@ std::unique_ptr<SSHMaster::Connection> SSHMaster::startCommand(
         close(in.writeSide.get());
         close(out.readSide.get());
 
-        if (dup2(in.readSide.get(), STDIN_FILENO) == -1)
+        if (dup2(in.readSide.get(), STDIN_FILENO) == -1) {
           throw SysError("duping over stdin");
-        if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
+        }
+        if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1) {
           throw SysError("duping over stdout");
-        if (logFD != -1 && dup2(logFD, STDERR_FILENO) == -1)
+        }
+        if (logFD != -1 && dup2(logFD, STDERR_FILENO) == -1) {
           throw SysError("duping over stderr");
+        }
 
         Strings args;
 
@@ -112,8 +117,9 @@ Path SSHMaster::startMaster() {
 
         close(out.readSide.get());
 
-        if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
+        if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1) {
           throw SysError("duping over stdout");
+        }
 
         Strings args = {"ssh", host.c_str(),
                         "-M",  "-N",
@@ -136,8 +142,9 @@ Path SSHMaster::startMaster() {
   } catch (EndOfFile& e) {
   }
 
-  if (reply != "started")
+  if (reply != "started") {
     throw Error("failed to start SSH master connection to '%s'", host);
+  }
 
   return state->socketPath;
 }
diff --git a/third_party/nix/src/libstore/store-api.cc b/third_party/nix/src/libstore/store-api.cc
index 2a7b6a1ac4..7658a51100 100644
--- a/third_party/nix/src/libstore/store-api.cc
+++ b/third_party/nix/src/libstore/store-api.cc
@@ -25,18 +25,21 @@ bool Store::isStorePath(const Path& path) const {
 }
 
 void Store::assertStorePath(const Path& path) const {
-  if (!isStorePath(path))
+  if (!isStorePath(path)) {
     throw Error(format("path '%1%' is not in the Nix store") % path);
+  }
 }
 
 Path Store::toStorePath(const Path& path) const {
-  if (!isInStore(path))
+  if (!isInStore(path)) {
     throw Error(format("path '%1%' is not in the Nix store") % path);
+  }
   Path::size_type slash = path.find('/', storeDir.size() + 1);
-  if (slash == Path::npos)
+  if (slash == Path::npos) {
     return path;
-  else
+  } else {
     return Path(path, 0, slash);
+  }
 }
 
 Path Store::followLinksToStore(const Path& _path) const {
@@ -48,8 +51,9 @@ Path Store::followLinksToStore(const Path& _path) const {
     string target = readLink(path);
     path = absPath(target, dirOf(path));
   }
-  if (!isInStore(path))
+  if (!isInStore(path)) {
     throw Error(format("path '%1%' is not in the Nix store") % path);
+  }
   return path;
 }
 
@@ -86,17 +90,20 @@ void checkStoreName(const string& name) {
 
   /* Disallow names starting with a dot for possible security
      reasons (e.g., "." and ".."). */
-  if (string(name, 0, 1) == ".")
+  if (string(name, 0, 1) == ".") {
     throw Error(baseError % "it is illegal to start the name with a period");
+  }
   /* Disallow names longer than 211 characters. ext4’s max is 256,
      but we need extra space for the hash and .chroot extensions. */
-  if (name.length() > 211)
+  if (name.length() > 211) {
     throw Error(baseError % "name must be less than 212 characters");
-  for (auto& i : name)
+  }
+  for (auto& i : name) {
     if (!((i >= 'A' && i <= 'Z') || (i >= 'a' && i <= 'z') ||
           (i >= '0' && i <= '9') || validChars.find(i) != string::npos)) {
       throw Error(baseError % (format("the '%1%' character is invalid") % i));
     }
+  }
 }
 
 /* Store paths have the following form:
@@ -261,9 +268,10 @@ bool Store::isValidPath(const Path& storePath) {
 
   bool valid = isValidPathUncached(storePath);
 
-  if (diskCache && !valid)
+  if (diskCache && !valid) {
     // FIXME: handle valid = true case.
     diskCache->upsertNarInfo(getUri(), hashPart, 0);
+  }
 
   return valid;
 }
@@ -306,8 +314,9 @@ void Store::queryPathInfo(const Path& storePath,
       auto res = state.lock()->pathInfoCache.get(hashPart);
       if (res) {
         stats.narInfoReadAverted++;
-        if (!*res)
+        if (!*res) {
           throw InvalidPath(format("path '%s' is not valid") % storePath);
+        }
         return callback(ref<ValidPathInfo>(*res));
       }
     }
@@ -323,8 +332,9 @@ void Store::queryPathInfo(const Path& storePath,
               res.first == NarInfoDiskCache::oInvalid ? 0 : res.second);
           if (res.first == NarInfoDiskCache::oInvalid ||
               (res.second->path != storePath &&
-               storePathToName(storePath) != ""))
+               storePathToName(storePath) != "")) {
             throw InvalidPath(format("path '%s' is not valid") % storePath);
+          }
         }
         return callback(ref<ValidPathInfo>(res.second));
       }
@@ -483,8 +493,9 @@ void Store::pathInfoToJSON(JSONPlaceholder& jsonOut, const PathSet& storePaths,
           jsonPath.attr("deriver", info->deriver);
         }
 
-        if (info->registrationTime)
+        if (info->registrationTime) {
           jsonPath.attr("registrationTime", info->registrationTime);
+        }
 
         if (info->ultimate) {
           jsonPath.attr("ultimate", info->ultimate);
@@ -504,12 +515,15 @@ void Store::pathInfoToJSON(JSONPlaceholder& jsonOut, const PathSet& storePaths,
           if (!narInfo->url.empty()) {
             jsonPath.attr("url", narInfo->url);
           }
-          if (narInfo->fileHash)
+          if (narInfo->fileHash) {
             jsonPath.attr("downloadHash", narInfo->fileHash.to_string());
-          if (narInfo->fileSize)
+          }
+          if (narInfo->fileSize) {
             jsonPath.attr("downloadSize", narInfo->fileSize);
-          if (showClosureSize)
+          }
+          if (showClosureSize) {
             jsonPath.attr("closureDownloadSize", closureSizes.second);
+          }
         }
       }
 
@@ -544,10 +558,11 @@ const Store::Stats& Store::getStats() {
 }
 
 void Store::buildPaths(const PathSet& paths, BuildMode buildMode) {
-  for (auto& path : paths)
+  for (auto& path : paths) {
     if (isDerivation(path)) {
       unsupported("buildPaths");
     }
+  }
 
   if (queryValidPaths(paths).size() != paths.size()) {
     unsupported("buildPaths");
@@ -621,10 +636,11 @@ void copyPaths(ref<Store> srcStore, ref<Store> dstStore,
   PathSet valid = dstStore->queryValidPaths(storePaths, substitute);
 
   PathSet missing;
-  for (auto& path : storePaths)
+  for (auto& path : storePaths) {
     if (!valid.count(path)) {
       missing.insert(path);
     }
+  }
 
   if (missing.empty()) {
     return;
@@ -729,10 +745,11 @@ string showPaths(const PathSet& paths) {
 }
 
 std::string ValidPathInfo::fingerprint() const {
-  if (narSize == 0 || !narHash)
+  if (narSize == 0 || !narHash) {
     throw Error(format("cannot calculate fingerprint of path '%s' because its "
                        "size/hash is not known") %
                 path);
+  }
   return "1;" + path + ";" + narHash.to_string(Base32) + ";" +
          std::to_string(narSize) + ";" + concatStringsSep(",", references);
 }
@@ -749,10 +766,11 @@ bool ValidPathInfo::isContentAddressed(const Store& store) const {
 
   if (hasPrefix(ca, "text:")) {
     Hash hash(std::string(ca, 5));
-    if (store.makeTextPath(storePathToName(path), hash, references) == path)
+    if (store.makeTextPath(storePathToName(path), hash, references) == path) {
       return true;
-    else
+    } else {
       warn();
+    }
   }
 
   else if (hasPrefix(ca, "fixed:")) {
@@ -760,10 +778,11 @@ bool ValidPathInfo::isContentAddressed(const Store& store) const {
     Hash hash(std::string(ca, recursive ? 8 : 6));
     if (references.empty() &&
         store.makeFixedOutputPath(recursive, hash, storePathToName(path)) ==
-            path)
+            path) {
       return true;
-    else
+    } else {
       warn();
+    }
   }
 
   return false;
@@ -776,10 +795,11 @@ size_t ValidPathInfo::checkSignatures(const Store& store,
   }
 
   size_t good = 0;
-  for (auto& sig : sigs)
+  for (auto& sig : sigs) {
     if (checkSignature(publicKeys, sig)) {
       good++;
     }
+  }
   return good;
 }
 
@@ -838,16 +858,18 @@ std::pair<std::string, Store::Params> splitUriAndParams(
         std::string decoded;
         for (size_t i = 0; i < value.size();) {
           if (value[i] == '%') {
-            if (i + 2 >= value.size())
+            if (i + 2 >= value.size()) {
               throw Error("invalid URI parameter '%s'", value);
+            }
             try {
               decoded += std::stoul(std::string(value, i + 1, 2), 0, 16);
               i += 3;
             } catch (...) {
               throw Error("invalid URI parameter '%s'", value);
             }
-          } else
+          } else {
             decoded += value[i++];
+          }
         }
         params[s.substr(0, e)] = decoded;
       }
@@ -880,9 +902,9 @@ StoreType getStoreType(const std::string& uri, const std::string& stateDir) {
   } else if (uri == "local" || hasPrefix(uri, "/")) {
     return tLocal;
   } else if (uri == "" || uri == "auto") {
-    if (access(stateDir.c_str(), R_OK | W_OK) == 0)
+    if (access(stateDir.c_str(), R_OK | W_OK) == 0) {
       return tLocal;
-    else if (pathExists(settings.nixDaemonSocketFile)) {
+    } else if (pathExists(settings.nixDaemonSocketFile)) {
       return tDaemon;
     } else {
       return tLocal;
diff --git a/third_party/nix/src/libutil/archive.cc b/third_party/nix/src/libutil/archive.cc
index a86170b315..855a3c4658 100644
--- a/third_party/nix/src/libutil/archive.cc
+++ b/third_party/nix/src/libutil/archive.cc
@@ -76,9 +76,10 @@ static void dump(const Path& path, Sink& sink, PathFilter& filter) {
   if (S_ISREG(st.st_mode)) {
     sink << "type"
          << "regular";
-    if (st.st_mode & S_IXUSR)
+    if (st.st_mode & S_IXUSR) {
       sink << "executable"
            << "";
+    }
     dumpContents(path, (size_t)st.st_size, sink);
   }
 
@@ -89,7 +90,7 @@ static void dump(const Path& path, Sink& sink, PathFilter& filter) {
     /* If we're on a case-insensitive system like macOS, undo
        the case hack applied by restorePath(). */
     std::map<string, string> unhacked;
-    for (auto& i : readDirectory(path))
+    for (auto& i : readDirectory(path)) {
       if (archiveSettings.useCaseHack) {
         string name(i.name);
         size_t pos = i.name.find(caseHackSuffix);
@@ -99,14 +100,17 @@ static void dump(const Path& path, Sink& sink, PathFilter& filter) {
 
           name.erase(pos);
         }
-        if (unhacked.find(name) != unhacked.end())
+        if (unhacked.find(name) != unhacked.end()) {
           throw Error(format("file name collision in between '%1%' and '%2%'") %
                       (path + "/" + unhacked[name]) % (path + "/" + i.name));
+        }
         unhacked[name] = i.name;
-      } else
+      } else {
         unhacked[i.name] = i.name;
+      }
+    }
 
-    for (auto& i : unhacked)
+    for (auto& i : unhacked) {
       if (filter(path + "/" + i.first)) {
         sink << "entry"
              << "("
@@ -114,15 +118,17 @@ static void dump(const Path& path, Sink& sink, PathFilter& filter) {
         dump(path + "/" + i.second, sink, filter);
         sink << ")";
       }
+    }
   }
 
-  else if (S_ISLNK(st.st_mode))
+  else if (S_ISLNK(st.st_mode)) {
     sink << "type"
          << "symlink"
          << "target" << readLink(path);
 
-  else
+  } else {
     throw Error(format("file '%1%' has an unsupported type") % path);
+  }
 
   sink << ")";
 }
@@ -222,8 +228,9 @@ static void parse(ParseSink& sink, Source& source, const Path& path) {
         type = tpSymlink;
       }
 
-      else
+      else {
         throw badArchive("unknown file type " + t);
+      }
 
     }
 
@@ -258,8 +265,9 @@ static void parse(ParseSink& sink, Source& source, const Path& path) {
           name = readString(source);
           if (name.empty() || name == "." || name == ".." ||
               name.find('/') != string::npos ||
-              name.find((char)0) != string::npos)
+              name.find((char)0) != string::npos) {
             throw Error(format("NAR contains invalid file name '%1%'") % name);
+          }
           if (name <= prevName) {
             throw Error("NAR directory is not sorted");
           }
@@ -271,16 +279,18 @@ static void parse(ParseSink& sink, Source& source, const Path& path) {
                          << name << "'";
               name += caseHackSuffix;
               name += std::to_string(++i->second);
-            } else
+            } else {
               names[name] = 0;
+            }
           }
         } else if (s == "node") {
           if (s.empty()) {
             throw badArchive("entry name missing");
           }
           parse(sink, source, path + "/" + name);
-        } else
+        } else {
           throw badArchive("unknown field " + s);
+        }
       }
     }
 
@@ -289,8 +299,9 @@ static void parse(ParseSink& sink, Source& source, const Path& path) {
       sink.createSymlink(path, target);
     }
 
-    else
+    else {
       throw badArchive("unknown field " + s);
+    }
   }
 }
 
@@ -302,8 +313,9 @@ void parseDump(ParseSink& sink, Source& source) {
     /* This generally means the integer at the start couldn't be
        decoded.  Ignore and throw the exception below. */
   }
-  if (version != narVersionMagic1)
+  if (version != narVersionMagic1) {
     throw badArchive("input doesn't look like a Nix archive");
+  }
   parse(sink, source, "");
 }
 
@@ -313,8 +325,9 @@ struct RestoreSink : ParseSink {
 
   void createDirectory(const Path& path) {
     Path p = dstPath + path;
-    if (mkdir(p.c_str(), 0777) == -1)
+    if (mkdir(p.c_str(), 0777) == -1) {
       throw SysError(format("creating directory '%1%'") % p);
+    }
   };
 
   void createRegularFile(const Path& path) {
@@ -330,8 +343,9 @@ struct RestoreSink : ParseSink {
     if (fstat(fd.get(), &st) == -1) {
       throw SysError("fstat");
     }
-    if (fchmod(fd.get(), st.st_mode | (S_IXUSR | S_IXGRP | S_IXOTH)) == -1)
+    if (fchmod(fd.get(), st.st_mode | (S_IXUSR | S_IXGRP | S_IXOTH)) == -1) {
       throw SysError("fchmod");
+    }
   }
 
   void preallocateContents(unsigned long long len) {
@@ -342,8 +356,9 @@ struct RestoreSink : ParseSink {
          filesystem doesn't support preallocation (e.g. on
          OpenSolaris).  Since preallocation is just an
          optimisation, ignore it. */
-      if (errno && errno != EINVAL && errno != EOPNOTSUPP && errno != ENOSYS)
+      if (errno && errno != EINVAL && errno != EOPNOTSUPP && errno != ENOSYS) {
         throw SysError(format("preallocating file of %1% bytes") % len);
+      }
     }
 #endif
   }
diff --git a/third_party/nix/src/libutil/args.cc b/third_party/nix/src/libutil/args.cc
index be1d915819..92343d88e5 100644
--- a/third_party/nix/src/libutil/args.cc
+++ b/third_party/nix/src/libutil/args.cc
@@ -30,13 +30,14 @@ void Args::parseCmdline(const Strings& _cmdline) {
       *pos = (string) "-" + arg[1];
       auto next = pos;
       ++next;
-      for (unsigned int j = 2; j < arg.length(); j++)
-        if (isalpha(arg[j]))
+      for (unsigned int j = 2; j < arg.length(); j++) {
+        if (isalpha(arg[j])) {
           cmdline.insert(next, (string) "-" + arg[j]);
-        else {
+        } else {
           cmdline.insert(next, string(arg, j));
           break;
         }
+      }
       arg = *pos;
     }
 
@@ -44,8 +45,9 @@ void Args::parseCmdline(const Strings& _cmdline) {
       dashDash = true;
       ++pos;
     } else if (!dashDash && std::string(arg, 0, 1) == "-") {
-      if (!processFlag(pos, cmdline.end()))
+      if (!processFlag(pos, cmdline.end())) {
         throw UsageError(format("unrecognised flag '%1%'") % arg);
+      }
     } else {
       pendingArgs.push_back(*pos++);
       if (processArgs(pendingArgs, false)) {
@@ -141,8 +143,9 @@ bool Args::processFlag(Strings::iterator& pos, Strings::iterator end) {
 
 bool Args::processArgs(const Strings& args, bool finish) {
   if (expectedArgs.empty()) {
-    if (!args.empty())
+    if (!args.empty()) {
       throw UsageError(format("unexpected argument '%1%'") % args.front());
+    }
     return true;
   }
 
@@ -161,8 +164,9 @@ bool Args::processArgs(const Strings& args, bool finish) {
     res = true;
   }
 
-  if (finish && !expectedArgs.empty() && !expectedArgs.front().optional)
+  if (finish && !expectedArgs.empty() && !expectedArgs.front().optional) {
     throw UsageError("more arguments are required");
+  }
 
   return res;
 }
@@ -184,7 +188,9 @@ Strings argvToStrings(int argc, char** argv) {
   Strings args;
   argc--;
   argv++;
-  while (argc--) args.push_back(*argv++);
+  while (argc--) {
+    args.push_back(*argv++);
+  }
   return args;
 }
 
diff --git a/third_party/nix/src/libutil/compression.cc b/third_party/nix/src/libutil/compression.cc
index 219d9046fa..e13ffcec74 100644
--- a/third_party/nix/src/libutil/compression.cc
+++ b/third_party/nix/src/libutil/compression.cc
@@ -49,8 +49,9 @@ struct XzDecompressionSink : CompressionSink {
 
   XzDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
     lzma_ret ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
-    if (ret != LZMA_OK)
+    if (ret != LZMA_OK) {
       throw CompressionError("unable to initialise lzma decoder");
+    }
 
     strm.next_out = outbuf;
     strm.avail_out = sizeof(outbuf);
@@ -71,8 +72,9 @@ struct XzDecompressionSink : CompressionSink {
       checkInterrupt();
 
       lzma_ret ret = lzma_code(&strm, data ? LZMA_RUN : LZMA_FINISH);
-      if (ret != LZMA_OK && ret != LZMA_STREAM_END)
+      if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
         throw CompressionError("error %d while decompressing xz file", ret);
+      }
 
       finished = ret == LZMA_STREAM_END;
 
@@ -93,8 +95,9 @@ struct BzipDecompressionSink : ChunkedCompressionSink {
   BzipDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
     memset(&strm, 0, sizeof(strm));
     int ret = BZ2_bzDecompressInit(&strm, 0, 0);
-    if (ret != BZ_OK)
+    if (ret != BZ_OK) {
       throw CompressionError("unable to initialise bzip2 decoder");
+    }
 
     strm.next_out = (char*)outbuf;
     strm.avail_out = sizeof(outbuf);
@@ -117,8 +120,9 @@ struct BzipDecompressionSink : ChunkedCompressionSink {
       checkInterrupt();
 
       int ret = BZ2_bzDecompress(&strm);
-      if (ret != BZ_OK && ret != BZ_STREAM_END)
+      if (ret != BZ_OK && ret != BZ_STREAM_END) {
         throw CompressionError("error while decompressing bzip2 file");
+      }
 
       finished = ret == BZ_STREAM_END;
 
@@ -160,8 +164,9 @@ struct BrotliDecompressionSink : ChunkedCompressionSink {
       checkInterrupt();
 
       if (!BrotliDecoderDecompressStream(state, &avail_in, &next_in, &avail_out,
-                                         &next_out, nullptr))
+                                         &next_out, nullptr)) {
         throw CompressionError("error while decompressing brotli file");
+      }
 
       if (avail_out < sizeof(outbuf) || avail_in == 0) {
         nextSink(outbuf, sizeof(outbuf) - avail_out);
@@ -184,16 +189,17 @@ ref<std::string> decompress(const std::string& method, const std::string& in) {
 
 ref<CompressionSink> makeDecompressionSink(const std::string& method,
                                            Sink& nextSink) {
-  if (method == "none" || method == "")
+  if (method == "none" || method == "") {
     return make_ref<NoneSink>(nextSink);
-  else if (method == "xz")
+  } else if (method == "xz") {
     return make_ref<XzDecompressionSink>(nextSink);
-  else if (method == "bzip2")
+  } else if (method == "bzip2") {
     return make_ref<BzipDecompressionSink>(nextSink);
-  else if (method == "br")
+  } else if (method == "br") {
     return make_ref<BrotliDecompressionSink>(nextSink);
-  else
+  } else {
     throw UnknownCompressionMethod("unknown compression method '%s'", method);
+  }
 }
 
 struct XzCompressionSink : CompressionSink {
@@ -258,8 +264,9 @@ struct XzCompressionSink : CompressionSink {
       checkInterrupt();
 
       lzma_ret ret = lzma_code(&strm, data ? LZMA_RUN : LZMA_FINISH);
-      if (ret != LZMA_OK && ret != LZMA_STREAM_END)
+      if (ret != LZMA_OK && ret != LZMA_STREAM_END) {
         throw CompressionError("error %d while compressing xz file", ret);
+      }
 
       finished = ret == LZMA_STREAM_END;
 
@@ -280,8 +287,9 @@ struct BzipCompressionSink : ChunkedCompressionSink {
   BzipCompressionSink(Sink& nextSink) : nextSink(nextSink) {
     memset(&strm, 0, sizeof(strm));
     int ret = BZ2_bzCompressInit(&strm, 9, 0, 30);
-    if (ret != BZ_OK)
+    if (ret != BZ_OK) {
       throw CompressionError("unable to initialise bzip2 encoder");
+    }
 
     strm.next_out = (char*)outbuf;
     strm.avail_out = sizeof(outbuf);
@@ -304,8 +312,9 @@ struct BzipCompressionSink : ChunkedCompressionSink {
       checkInterrupt();
 
       int ret = BZ2_bzCompress(&strm, data ? BZ_RUN : BZ_FINISH);
-      if (ret != BZ_RUN_OK && ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
+      if (ret != BZ_RUN_OK && ret != BZ_FINISH_OK && ret != BZ_STREAM_END) {
         throw CompressionError("error %d while compressing bzip2 file", ret);
+      }
 
       finished = ret == BZ_STREAM_END;
 
@@ -349,8 +358,9 @@ struct BrotliCompressionSink : ChunkedCompressionSink {
 
       if (!BrotliEncoderCompressStream(
               state, data ? BROTLI_OPERATION_PROCESS : BROTLI_OPERATION_FINISH,
-              &avail_in, &next_in, &avail_out, &next_out, nullptr))
+              &avail_in, &next_in, &avail_out, &next_out, nullptr)) {
         throw CompressionError("error while compressing brotli compression");
+      }
 
       if (avail_out < sizeof(outbuf) || avail_in == 0) {
         nextSink(outbuf, sizeof(outbuf) - avail_out);
@@ -365,17 +375,18 @@ struct BrotliCompressionSink : ChunkedCompressionSink {
 
 ref<CompressionSink> makeCompressionSink(const std::string& method,
                                          Sink& nextSink, const bool parallel) {
-  if (method == "none")
+  if (method == "none") {
     return make_ref<NoneSink>(nextSink);
-  else if (method == "xz")
+  } else if (method == "xz") {
     return make_ref<XzCompressionSink>(nextSink, parallel);
-  else if (method == "bzip2")
+  } else if (method == "bzip2") {
     return make_ref<BzipCompressionSink>(nextSink);
-  else if (method == "br")
+  } else if (method == "br") {
     return make_ref<BrotliCompressionSink>(nextSink);
-  else
+  } else {
     throw UnknownCompressionMethod(format("unknown compression method '%s'") %
                                    method);
+  }
 }
 
 ref<std::string> compress(const std::string& method, const std::string& in,
diff --git a/third_party/nix/src/libutil/config.cc b/third_party/nix/src/libutil/config.cc
index 0b01f6ae8a..9c8c6cf4b2 100644
--- a/third_party/nix/src/libutil/config.cc
+++ b/third_party/nix/src/libutil/config.cc
@@ -21,8 +21,9 @@ bool Config::set(const std::string& name, const std::string& value) {
 
 void Config::addSetting(AbstractSetting* setting) {
   _settings.emplace(setting->name, Config::SettingData(false, setting));
-  for (auto& alias : setting->aliases)
+  for (auto& alias : setting->aliases) {
     _settings.emplace(alias, Config::SettingData(true, setting));
+  }
 
   bool set = false;
 
@@ -68,11 +69,13 @@ void AbstractConfig::reapplyUnknownSettings() {
 
 void Config::getSettings(std::map<std::string, SettingInfo>& res,
                          bool overridenOnly) {
-  for (auto& opt : _settings)
+  for (auto& opt : _settings) {
     if (!opt.second.isAlias &&
-        (!overridenOnly || opt.second.setting->overriden))
+        (!overridenOnly || opt.second.setting->overriden)) {
       res.emplace(opt.first, SettingInfo{opt.second.setting->to_string(),
                                          opt.second.setting->description});
+    }
+  }
 }
 
 void AbstractConfig::applyConfigFile(const Path& path) {
@@ -83,8 +86,9 @@ void AbstractConfig::applyConfigFile(const Path& path) {
 
     while (pos < contents.size()) {
       string line;
-      while (pos < contents.size() && contents[pos] != '\n')
+      while (pos < contents.size() && contents[pos] != '\n') {
         line += contents[pos++];
+      }
       pos++;
 
       string::size_type hash = line.find('#');
@@ -97,23 +101,25 @@ void AbstractConfig::applyConfigFile(const Path& path) {
         continue;
       }
 
-      if (tokens.size() < 2)
+      if (tokens.size() < 2) {
         throw UsageError("illegal configuration line '%1%' in '%2%'", line,
                          path);
+      }
 
       auto include = false;
       auto ignoreMissing = false;
-      if (tokens[0] == "include")
+      if (tokens[0] == "include") {
         include = true;
-      else if (tokens[0] == "!include") {
+      } else if (tokens[0] == "!include") {
         include = true;
         ignoreMissing = true;
       }
 
       if (include) {
-        if (tokens.size() != 2)
+        if (tokens.size() != 2) {
           throw UsageError("illegal configuration line '%1%' in '%2%'", line,
                            path);
+        }
         auto p = absPath(tokens[1], dirOf(path));
         if (pathExists(p)) {
           applyConfigFile(p);
@@ -123,9 +129,10 @@ void AbstractConfig::applyConfigFile(const Path& path) {
         continue;
       }
 
-      if (tokens[1] != "=")
+      if (tokens[1] != "=") {
         throw UsageError("illegal configuration line '%1%' in '%2%'", line,
                          path);
+      }
 
       string name = tokens[0];
 
@@ -146,20 +153,22 @@ void Config::resetOverriden() {
 }
 
 void Config::toJSON(JSONObject& out) {
-  for (auto& s : _settings)
+  for (auto& s : _settings) {
     if (!s.second.isAlias) {
       JSONObject out2(out.object(s.first));
       out2.attr("description", s.second.setting->description);
       JSONPlaceholder out3(out2.placeholder("value"));
       s.second.setting->toJSON(out3);
     }
+  }
 }
 
 void Config::convertToArgs(Args& args, const std::string& category) {
-  for (auto& s : _settings)
+  for (auto& s : _settings) {
     if (!s.second.isAlias) {
       s.second.setting->convertToArg(args, category);
     }
+  }
 }
 
 AbstractSetting::AbstractSetting(const std::string& name,
@@ -202,8 +211,9 @@ std::string BaseSetting<std::string>::to_string() {
 template <typename T>
 void BaseSetting<T>::set(const std::string& str) {
   static_assert(std::is_integral<T>::value, "Integer required.");
-  if (!string2Int(str, value))
+  if (!string2Int(str, value)) {
     throw UsageError("setting '%s' has invalid value '%s'", name, str);
+  }
 }
 
 template <typename T>
@@ -214,12 +224,13 @@ std::string BaseSetting<T>::to_string() {
 
 template <>
 void BaseSetting<bool>::set(const std::string& str) {
-  if (str == "true" || str == "yes" || str == "1")
+  if (str == "true" || str == "yes" || str == "1") {
     value = true;
-  else if (str == "false" || str == "no" || str == "0")
+  } else if (str == "false" || str == "no" || str == "0") {
     value = false;
-  else
+  } else {
     throw UsageError("Boolean setting '%s' has invalid value '%s'", name, str);
+  }
 }
 
 template <>
@@ -290,19 +301,22 @@ template class BaseSetting<StringSet>;
 
 void PathSetting::set(const std::string& str) {
   if (str == "") {
-    if (allowEmpty)
+    if (allowEmpty) {
       value = "";
-    else
+    } else {
       throw UsageError("setting '%s' cannot be empty", name);
-  } else
+    }
+  } else {
     value = canonPath(str);
+  }
 }
 
 bool GlobalConfig::set(const std::string& name, const std::string& value) {
-  for (auto& config : *configRegistrations)
+  for (auto& config : *configRegistrations) {
     if (config->set(name, value)) {
       return true;
     }
+  }
 
   unknownSettings.emplace(name, value);
 
@@ -311,8 +325,9 @@ bool GlobalConfig::set(const std::string& name, const std::string& value) {
 
 void GlobalConfig::getSettings(std::map<std::string, SettingInfo>& res,
                                bool overridenOnly) {
-  for (auto& config : *configRegistrations)
+  for (auto& config : *configRegistrations) {
     config->getSettings(res, overridenOnly);
+  }
 }
 
 void GlobalConfig::resetOverriden() {
@@ -328,8 +343,9 @@ void GlobalConfig::toJSON(JSONObject& out) {
 }
 
 void GlobalConfig::convertToArgs(Args& args, const std::string& category) {
-  for (auto& config : *configRegistrations)
+  for (auto& config : *configRegistrations) {
     config->convertToArgs(args, category);
+  }
 }
 
 GlobalConfig globalConfig;
diff --git a/third_party/nix/src/libutil/hash.cc b/third_party/nix/src/libutil/hash.cc
index 0a0869dd4e..e33c76cc90 100644
--- a/third_party/nix/src/libutil/hash.cc
+++ b/third_party/nix/src/libutil/hash.cc
@@ -132,8 +132,9 @@ Hash::Hash(const std::string& s, HashType type) : type(type) {
     sep = s.find('-');
     if (sep != string::npos) {
       isSRI = true;
-    } else if (type == htUnknown)
+    } else if (type == htUnknown) {
       throw BadHash("hash '%s' does not include a type", s);
+    }
   }
 
   if (sep != string::npos) {
@@ -142,8 +143,9 @@ Hash::Hash(const std::string& s, HashType type) : type(type) {
     if (this->type == htUnknown) {
       throw BadHash("unknown hash type '%s'", hts);
     }
-    if (type != htUnknown && type != this->type)
+    if (type != htUnknown && type != this->type) {
       throw BadHash("hash '%s' should have type '%s'", s, printHashType(type));
+    }
     pos = sep + 1;
   }
 
@@ -175,10 +177,11 @@ Hash::Hash(const std::string& s, HashType type) : type(type) {
     for (unsigned int n = 0; n < size; ++n) {
       char c = s[pos + size - n - 1];
       unsigned char digit;
-      for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */
+      for (digit = 0; digit < base32Chars.size(); ++digit) { /* !!! slow */
         if (base32Chars[digit] == c) {
           break;
         }
+      }
       if (digit >= 32) {
         throw BadHash("invalid base-32 hash '%s'", s);
       }
@@ -199,15 +202,17 @@ Hash::Hash(const std::string& s, HashType type) : type(type) {
 
   else if (isSRI || size == base64Len()) {
     auto d = base64Decode(std::string(s, pos));
-    if (d.size() != hashSize)
+    if (d.size() != hashSize) {
       throw BadHash("invalid %s hash '%s'", isSRI ? "SRI" : "base-64", s);
+    }
     assert(hashSize);
     memcpy(hash, d.data(), hashSize);
   }
 
-  else
+  else {
     throw BadHash("hash '%s' has wrong length for hash type '%s'", s,
                   printHashType(type));
+  }
 }
 
 union Ctx {
@@ -218,37 +223,40 @@ union Ctx {
 };
 
 static void start(HashType ht, Ctx& ctx) {
-  if (ht == htMD5)
+  if (ht == htMD5) {
     MD5_Init(&ctx.md5);
-  else if (ht == htSHA1)
+  } else if (ht == htSHA1) {
     SHA1_Init(&ctx.sha1);
-  else if (ht == htSHA256)
+  } else if (ht == htSHA256) {
     SHA256_Init(&ctx.sha256);
-  else if (ht == htSHA512)
+  } else if (ht == htSHA512) {
     SHA512_Init(&ctx.sha512);
+  }
 }
 
 static void update(HashType ht, Ctx& ctx, const unsigned char* bytes,
                    size_t len) {
-  if (ht == htMD5)
+  if (ht == htMD5) {
     MD5_Update(&ctx.md5, bytes, len);
-  else if (ht == htSHA1)
+  } else if (ht == htSHA1) {
     SHA1_Update(&ctx.sha1, bytes, len);
-  else if (ht == htSHA256)
+  } else if (ht == htSHA256) {
     SHA256_Update(&ctx.sha256, bytes, len);
-  else if (ht == htSHA512)
+  } else if (ht == htSHA512) {
     SHA512_Update(&ctx.sha512, bytes, len);
+  }
 }
 
 static void finish(HashType ht, Ctx& ctx, unsigned char* hash) {
-  if (ht == htMD5)
+  if (ht == htMD5) {
     MD5_Final(hash, &ctx.md5);
-  else if (ht == htSHA1)
+  } else if (ht == htSHA1) {
     SHA1_Final(hash, &ctx.sha1);
-  else if (ht == htSHA256)
+  } else if (ht == htSHA256) {
     SHA256_Final(hash, &ctx.sha256);
-  else if (ht == htSHA512)
+  } else if (ht == htSHA512) {
     SHA512_Final(hash, &ctx.sha512);
+  }
 }
 
 Hash hashString(HashType ht, const string& s) {
@@ -331,29 +339,31 @@ Hash compressHash(const Hash& hash, unsigned int newSize) {
 }
 
 HashType parseHashType(const string& s) {
-  if (s == "md5")
+  if (s == "md5") {
     return htMD5;
-  else if (s == "sha1")
+  } else if (s == "sha1") {
     return htSHA1;
-  else if (s == "sha256")
+  } else if (s == "sha256") {
     return htSHA256;
-  else if (s == "sha512")
+  } else if (s == "sha512") {
     return htSHA512;
-  else
+  } else {
     return htUnknown;
+  }
 }
 
 string printHashType(HashType ht) {
-  if (ht == htMD5)
+  if (ht == htMD5) {
     return "md5";
-  else if (ht == htSHA1)
+  } else if (ht == htSHA1) {
     return "sha1";
-  else if (ht == htSHA256)
+  } else if (ht == htSHA256) {
     return "sha256";
-  else if (ht == htSHA512)
+  } else if (ht == htSHA512) {
     return "sha512";
-  else
+  } else {
     abort();
+  }
 }
 
 }  // namespace nix
diff --git a/third_party/nix/src/libutil/json.cc b/third_party/nix/src/libutil/json.cc
index 7965f4725b..c5f52ae8ef 100644
--- a/third_party/nix/src/libutil/json.cc
+++ b/third_party/nix/src/libutil/json.cc
@@ -7,28 +7,31 @@ namespace nix {
 
 void toJSON(std::ostream& str, const char* start, const char* end) {
   str << '"';
-  for (auto i = start; i != end; i++)
-    if (*i == '\"' || *i == '\\')
+  for (auto i = start; i != end; i++) {
+    if (*i == '\"' || *i == '\\') {
       str << '\\' << *i;
-    else if (*i == '\n')
+    } else if (*i == '\n') {
       str << "\\n";
-    else if (*i == '\r')
+    } else if (*i == '\r') {
       str << "\\r";
-    else if (*i == '\t')
+    } else if (*i == '\t') {
       str << "\\t";
-    else if (*i >= 0 && *i < 32)
+    } else if (*i >= 0 && *i < 32) {
       str << "\\u" << std::setfill('0') << std::setw(4) << std::hex
           << (uint16_t)*i << std::dec;
-    else
+    } else {
       str << *i;
+    }
+  }
   str << '"';
 }
 
 void toJSON(std::ostream& str, const char* s) {
-  if (!s)
+  if (!s) {
     str << "null";
-  else
+  } else {
     toJSON(str, s, s + strlen(s));
+  }
 }
 
 template <>
diff --git a/third_party/nix/src/libutil/serialise.cc b/third_party/nix/src/libutil/serialise.cc
index 760d19ed4c..b51ed2105b 100644
--- a/third_party/nix/src/libutil/serialise.cc
+++ b/third_party/nix/src/libutil/serialise.cc
@@ -173,7 +173,7 @@ std::unique_ptr<Source> sinkToSource(std::function<void(Sink&)> fun,
     size_t pos = 0;
 
     size_t read(unsigned char* data, size_t len) override {
-      if (!coro)
+      if (!coro) {
         coro = coro_t::pull_type([&](coro_t::push_type& yield) {
           LambdaSink sink([&](const unsigned char* data, size_t len) {
             if (len) {
@@ -182,6 +182,7 @@ std::unique_ptr<Source> sinkToSource(std::function<void(Sink&)> fun,
           });
           fun(sink);
         });
+      }
 
       if (!*coro) {
         eof();
@@ -189,7 +190,9 @@ std::unique_ptr<Source> sinkToSource(std::function<void(Sink&)> fun,
       }
 
       if (pos == cur.size()) {
-        if (!cur.empty()) (*coro)();
+        if (!cur.empty()) {
+          (*coro)();
+        }
         cur = coro->get();
         pos = 0;
       }
@@ -247,10 +250,11 @@ void readPadding(size_t len, Source& source) {
     unsigned char zero[8];
     size_t n = 8 - (len % 8);
     source(zero, n);
-    for (unsigned int i = 0; i < n; i++)
+    for (unsigned int i = 0; i < n; i++) {
       if (zero[i]) {
         throw SerialisationError("non-zero padding");
       }
+    }
   }
 }
 
@@ -284,7 +288,9 @@ template <class T>
 T readStrings(Source& source) {
   auto count = readNum<size_t>(source);
   T ss;
-  while (count--) ss.insert(ss.end(), readString(source));
+  while (count--) {
+    ss.insert(ss.end(), readString(source));
+  }
   return ss;
 }
 
diff --git a/third_party/nix/src/libutil/thread-pool.cc b/third_party/nix/src/libutil/thread-pool.cc
index a16f4c2b60..d0042c6df1 100644
--- a/third_party/nix/src/libutil/thread-pool.cc
+++ b/third_party/nix/src/libutil/thread-pool.cc
@@ -50,8 +50,9 @@ void ThreadPool::enqueue(const work_t& t) {
   state->pending.push(t);
   /* Note: process() also executes items, so count it as a worker. */
   if (state->pending.size() > state->workers.size() + 1 &&
-      state->workers.size() + 1 < maxThreads)
+      state->workers.size() + 1 < maxThreads) {
     state->workers.emplace_back(&ThreadPool::doWork, this, false);
+  }
   work.notify_one();
 }
 
@@ -111,8 +112,9 @@ void ThreadPool::doWork(bool mainThread) {
               std::rethrow_exception(exc);
             } catch (std::exception& e) {
               if (!dynamic_cast<Interrupted*>(&e) &&
-                  !dynamic_cast<ThreadPoolShutDown*>(&e))
+                  !dynamic_cast<ThreadPoolShutDown*>(&e)) {
                 ignoreException();
+              }
             } catch (...) {
             }
           }
diff --git a/third_party/nix/src/libutil/util.cc b/third_party/nix/src/libutil/util.cc
index 3cc8563a86..213a9a0d6a 100644
--- a/third_party/nix/src/libutil/util.cc
+++ b/third_party/nix/src/libutil/util.cc
@@ -60,9 +60,10 @@ std::map<std::string, std::string> getEnv() {
   for (size_t i = 0; environ[i]; ++i) {
     auto s = environ[i];
     auto eq = strchr(s, '=');
-    if (!eq)
+    if (!eq) {
       // invalid env, just keep going
       continue;
+    }
     env.emplace(std::string(s, eq), std::string(eq + 1));
   }
   return env;
@@ -91,18 +92,19 @@ Path absPath(Path path, Path dir) {
       if (buf == NULL)
 #else
       char buf[PATH_MAX];
-      if (!getcwd(buf, sizeof(buf)))
+      if (!getcwd(buf, sizeof(buf))) {
 #endif
         throw SysError("cannot get cwd");
-      dir = buf;
+    }
+    dir = buf;
 #ifdef __GNU__
-      free(buf);
+    free(buf);
 #endif
-    }
-    path = dir + "/" + path;
   }
-  return canonPath(path);
+  path = dir + "/" + path;
 }
+return canonPath(path);
+}  // namespace nix
 
 Path canonPath(const Path& path, bool resolveSymlinks) {
   assert(path != "");
@@ -122,7 +124,9 @@ Path canonPath(const Path& path, bool resolveSymlinks) {
 
   while (1) {
     /* Skip slashes. */
-    while (i != end && *i == '/') i++;
+    while (i != end && *i == '/') {
+      i++;
+    }
     if (i == end) {
       break;
     }
@@ -144,14 +148,17 @@ Path canonPath(const Path& path, bool resolveSymlinks) {
     /* Normal component; copy it. */
     else {
       s += '/';
-      while (i != end && *i != '/') s += *i++;
+      while (i != end && *i != '/') {
+        s += *i++;
+      }
 
       /* If s points to a symlink, resolve it and restart (since
          the symlink target might contain new symlinks). */
       if (resolveSymlinks && isLink(s)) {
-        if (++followCount >= maxFollow)
+        if (++followCount >= maxFollow) {
           throw Error(format("infinite symlink recursion in path '%1%'") %
                       path);
+        }
         temp = absPath(readLink(s), dirOf(s)) + string(i, end);
         i = temp.begin(); /* restart */
         end = temp.end();
@@ -182,10 +189,11 @@ string baseNameOf(const Path& path) {
   }
 
   Path::size_type pos = path.rfind('/', last);
-  if (pos == string::npos)
+  if (pos == string::npos) {
     pos = 0;
-  else
+  } else {
     pos += 1;
+  }
 
   return string(path, pos, last - pos + 1);
 }
@@ -201,8 +209,9 @@ bool isDirOrInDir(const Path& path, const Path& dir) {
 
 struct stat lstat(const Path& path) {
   struct stat st;
-  if (lstat(path.c_str(), &st))
+  if (lstat(path.c_str(), &st)) {
     throw SysError(format("getting status of '%1%'") % path);
+  }
   return st;
 }
 
@@ -213,8 +222,9 @@ bool pathExists(const Path& path) {
   if (!res) {
     return true;
   }
-  if (errno != ENOENT && errno != ENOTDIR)
+  if (errno != ENOENT && errno != ENOTDIR) {
     throw SysError(format("getting status of %1%") % path);
+  }
   return false;
 }
 
@@ -224,13 +234,15 @@ Path readLink(const Path& path) {
   for (ssize_t bufSize = PATH_MAX / 4; true; bufSize += bufSize / 2) {
     buf.resize(bufSize);
     ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize);
-    if (rlSize == -1)
-      if (errno == EINVAL)
+    if (rlSize == -1) {
+      if (errno == EINVAL) {
         throw Error("'%1%' is not a symlink", path);
-      else
+      } else {
         throw SysError("reading symbolic link '%1%'", path);
-    else if (rlSize < bufSize)
+      }
+    } else if (rlSize < bufSize) {
       return string(buf.data(), rlSize);
+    }
   }
 }
 
@@ -351,9 +363,9 @@ string readLine(int fd) {
       if (errno != EINTR) {
         throw SysError("reading a line");
       }
-    } else if (rd == 0)
+    } else if (rd == 0) {
       throw EndOfFile("unexpected EOF reading a line");
-    else {
+    } else {
       if (ch == '\n') {
         return s;
       }
@@ -386,12 +398,14 @@ static void _deletePath(const Path& path, unsigned long long& bytesFreed) {
     /* Make the directory accessible. */
     const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR;
     if ((st.st_mode & PERM_MASK) != PERM_MASK) {
-      if (chmod(path.c_str(), st.st_mode | PERM_MASK) == -1)
+      if (chmod(path.c_str(), st.st_mode | PERM_MASK) == -1) {
         throw SysError(format("chmod '%1%'") % path);
+      }
     }
 
-    for (auto& i : readDirectory(path))
+    for (auto& i : readDirectory(path)) {
       _deletePath(path + "/" + i.name, bytesFreed);
+    }
   }
 
   if (remove(path.c_str()) == -1) {
@@ -418,11 +432,12 @@ static Path tempName(Path tmpRoot, const Path& prefix, bool includePid,
                      int& counter) {
   tmpRoot =
       canonPath(tmpRoot.empty() ? getEnv("TMPDIR", "/tmp") : tmpRoot, true);
-  if (includePid)
+  if (includePid) {
     return (format("%1%/%2%-%3%-%4%") % tmpRoot % prefix % getpid() % counter++)
         .str();
-  else
+  } else {
     return (format("%1%/%2%-%3%") % tmpRoot % prefix % counter++).str();
+  }
 }
 
 Path createTempDir(const Path& tmpRoot, const Path& prefix, bool includePid,
@@ -449,8 +464,9 @@ Path createTempDir(const Path& tmpRoot, const Path& prefix, bool includePid,
 #endif
       return tmpDir;
     }
-    if (errno != EEXIST)
+    if (errno != EEXIST) {
       throw SysError(format("creating directory '%1%'") % tmpDir);
+    }
   }
 }
 
@@ -470,8 +486,9 @@ static Lazy<Path> getHome2([]() {
     struct passwd pwbuf;
     struct passwd* pw;
     if (getpwuid_r(geteuid(), &pwbuf, buf.data(), buf.size(), &pw) != 0 ||
-        !pw || !pw->pw_dir || !pw->pw_dir[0])
+        !pw || !pw->pw_dir || !pw->pw_dir[0]) {
       throw Error("cannot determine user's home directory");
+    }
     homeDir = pw->pw_dir;
   }
   return homeDir;
@@ -521,25 +538,29 @@ Paths createDirs(const Path& path) {
   struct stat st;
   if (lstat(path.c_str(), &st) == -1) {
     created = createDirs(dirOf(path));
-    if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST)
+    if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) {
       throw SysError(format("creating directory '%1%'") % path);
+    }
     st = lstat(path);
     created.push_back(path);
   }
 
-  if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
+  if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) {
     throw SysError(format("statting symlink '%1%'") % path);
+  }
 
-  if (!S_ISDIR(st.st_mode))
+  if (!S_ISDIR(st.st_mode)) {
     throw Error(format("'%1%' is not a directory") % path);
+  }
 
   return created;
 }
 
 void createSymlink(const Path& target, const Path& link) {
-  if (symlink(target.c_str(), link.c_str()))
+  if (symlink(target.c_str(), link.c_str())) {
     throw SysError(format("creating symlink from '%1%' to '%2%'") % link %
                    target);
+  }
 }
 
 void replaceSymlink(const Path& target, const Path& link) {
@@ -555,8 +576,9 @@ void replaceSymlink(const Path& target, const Path& link) {
       throw;
     }
 
-    if (rename(tmp.c_str(), link.c_str()) != 0)
+    if (rename(tmp.c_str(), link.c_str()) != 0) {
       throw SysError(format("renaming '%1%' to '%2%'") % tmp % link);
+    }
 
     break;
   }
@@ -612,15 +634,17 @@ void drainFD(int fd, Sink& sink, bool block) {
 
   Finally finally([&]() {
     if (!block) {
-      if (fcntl(fd, F_SETFL, saved) == -1)
+      if (fcntl(fd, F_SETFL, saved) == -1) {
         throw SysError("making file descriptor blocking");
+      }
     }
   });
 
   if (!block) {
     saved = fcntl(fd, F_GETFL);
-    if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1)
+    if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1) {
       throw SysError("making file descriptor non-blocking");
+    }
   }
 
   std::vector<unsigned char> buf(64 * 1024);
@@ -634,10 +658,11 @@ void drainFD(int fd, Sink& sink, bool block) {
       if (errno != EINTR) {
         throw SysError("reading from file");
       }
-    } else if (rd == 0)
+    } else if (rd == 0) {
       break;
-    else
+    } else {
       sink(buf.data(), rd);
+    }
   }
 }
 
@@ -656,8 +681,9 @@ AutoDelete::~AutoDelete() {
       if (recursive) {
         deletePath(path);
       } else {
-        if (remove(path.c_str()) == -1)
+        if (remove(path.c_str()) == -1) {
           throw SysError(format("cannot unlink '%1%'") % path);
+        }
       }
     }
   } catch (...) {
@@ -700,8 +726,9 @@ int AutoCloseFD::get() const { return fd; }
 
 void AutoCloseFD::close() {
   if (fd != -1) {
-    if (::close(fd) == -1) /* This should never happen. */
+    if (::close(fd) == -1) { /* This should never happen. */
       throw SysError(format("closing file descriptor %1%") % fd);
+    }
   }
 }
 
@@ -835,8 +862,9 @@ void killUser(uid_t uid) {
           if (errno == ESRCH) {
             break;
           } /* no more processes */
-          if (errno != EINTR)
+          if (errno != EINTR) {
             throw SysError(format("cannot kill processes for uid '%1%'") % uid);
+          }
         }
 
         _exit(0);
@@ -844,9 +872,10 @@ void killUser(uid_t uid) {
       options);
 
   int status = pid.wait();
-  if (status != 0)
+  if (status != 0) {
     throw Error(format("cannot kill processes for uid '%1%': %2%") % uid %
                 statusToString(status));
+  }
 
   /* !!! We should really do some check to make sure that there are
      no processes left running under `uid', but there is no portable
@@ -877,8 +906,9 @@ pid_t startProcess(std::function<void()> fun, const ProcessOptions& options) {
   auto wrapper = [&]() {
     try {
 #if __linux__
-      if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1)
+      if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1) {
         throw SysError("setting death signal");
+      }
 #endif
       restoreAffinity();
       fun();
@@ -889,10 +919,11 @@ pid_t startProcess(std::function<void()> fun, const ProcessOptions& options) {
       }
     } catch (...) {
     }
-    if (options.runExitHandlers)
+    if (options.runExitHandlers) {
       exit(1);
-    else
+    } else {
       _exit(1);
+    }
   };
 
   pid_t pid = doFork(options.allowVfork, wrapper);
@@ -920,9 +951,10 @@ string runProgram(Path program, bool searchPath, const Strings& args,
 
   auto res = runProgram(opts);
 
-  if (!statusOk(res.first))
+  if (!statusOk(res.first)) {
     throw ExecError(res.first, fmt("program '%1%' %2%", program,
                                    statusToString(res.first)));
+  }
 
   return res.second;
 }
@@ -980,33 +1012,42 @@ void runProgram2(const RunOptions& options) {
           replaceEnv(*options.environment);
         }
         if (options.standardOut &&
-            dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
+            dup2(out.writeSide.get(), STDOUT_FILENO) == -1) {
           throw SysError("dupping stdout");
-        if (options.mergeStderrToStdout)
-          if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
+        }
+        if (options.mergeStderrToStdout) {
+          if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1) {
             throw SysError("cannot dup stdout into stderr");
-        if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1)
+          }
+        }
+        if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1) {
           throw SysError("dupping stdin");
+        }
 
-        if (options.chdir && chdir((*options.chdir).c_str()) == -1)
+        if (options.chdir && chdir((*options.chdir).c_str()) == -1) {
           throw SysError("chdir failed");
-        if (options.gid && setgid(*options.gid) == -1)
+        }
+        if (options.gid && setgid(*options.gid) == -1) {
           throw SysError("setgid failed");
+        }
         /* Drop all other groups if we're setgid. */
-        if (options.gid && setgroups(0, 0) == -1)
+        if (options.gid && setgroups(0, 0) == -1) {
           throw SysError("setgroups failed");
-        if (options.uid && setuid(*options.uid) == -1)
+        }
+        if (options.uid && setuid(*options.uid) == -1) {
           throw SysError("setuid failed");
+        }
 
         Strings args_(options.args);
         args_.push_front(options.program);
 
         restoreSignals();
 
-        if (options.searchPath)
+        if (options.searchPath) {
           execvp(options.program.c_str(), stringsToCharPtrs(args_).data());
-        else
+        } else {
           execv(options.program.c_str(), stringsToCharPtrs(args_).data());
+        }
 
         throw SysError("executing '%1%'", options.program);
       },
@@ -1058,9 +1099,10 @@ void runProgram2(const RunOptions& options) {
     promise.get_future().get();
   }
 
-  if (status)
+  if (status) {
     throw ExecError(status, fmt("program '%1%' %2%", options.program,
                                 statusToString(status)));
+  }
 }
 
 void closeMostFDs(const set<int>& exceptions) {
@@ -1080,17 +1122,19 @@ void closeMostFDs(const set<int>& exceptions) {
 
   int maxFD = 0;
   maxFD = sysconf(_SC_OPEN_MAX);
-  for (int fd = 0; fd < maxFD; ++fd)
+  for (int fd = 0; fd < maxFD; ++fd) {
     if (!exceptions.count(fd)) {
       close(fd);
     } /* ignore result */
+  }
 }
 
 void closeOnExec(int fd) {
   int prev;
   if ((prev = fcntl(fd, F_GETFD, 0)) == -1 ||
-      fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1)
+      fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1) {
     throw SysError("setting close-on-exec flag");
+  }
 }
 
 //////////////////////////////////////////////////////////////////////
@@ -1187,9 +1231,9 @@ string replaceStrings(const std::string& s, const std::string& from,
 
 string statusToString(int status) {
   if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-    if (WIFEXITED(status))
+    if (WIFEXITED(status)) {
       return (format("failed with exit code %1%") % WEXITSTATUS(status)).str();
-    else if (WIFSIGNALED(status)) {
+    } else if (WIFSIGNALED(status)) {
       int sig = WTERMSIG(status);
 #if HAVE_STRSIGNAL
       const char* description = strsignal(sig);
@@ -1198,10 +1242,12 @@ string statusToString(int status) {
 #else
       return (format("failed due to signal %1%") % sig).str();
 #endif
-    } else
+    } else {
       return "died abnormally";
-  } else
+    }
+  } else {
     return "succeeded";
+  }
 }
 
 bool statusOk(int status) {
@@ -1227,11 +1273,13 @@ std::string toLower(const std::string& s) {
 
 std::string shellEscape(const std::string& s) {
   std::string r = "'";
-  for (auto& i : s)
-    if (i == '\'')
+  for (auto& i : s) {
+    if (i == '\'') {
       r += "'\\''";
-    else
+    } else {
       r += i;
+    }
+  }
   r += '\'';
   return r;
 }
@@ -1259,9 +1307,13 @@ std::string filterANSIEscapes(const std::string& s, bool filterAll,
       if (i != s.end() && *i == '[') {
         e += *i++;
         // eat parameter bytes
-        while (i != s.end() && *i >= 0x30 && *i <= 0x3f) e += *i++;
+        while (i != s.end() && *i >= 0x30 && *i <= 0x3f) {
+          e += *i++;
+        }
         // eat intermediate bytes
-        while (i != s.end() && *i >= 0x20 && *i <= 0x2f) e += *i++;
+        while (i != s.end() && *i >= 0x20 && *i <= 0x2f) {
+          e += *i++;
+        }
         // eat final byte
         if (i != s.end() && *i >= 0x40 && *i <= 0x7e) {
           e += last = *i++;
@@ -1287,11 +1339,11 @@ std::string filterANSIEscapes(const std::string& s, bool filterAll,
       }
     }
 
-    else if (*i == '\r')
+    else if (*i == '\r') {
       // do nothing for now
       i++;
 
-    else {
+    } else {
       t += *i++;
       w++;
     }
@@ -1319,7 +1371,9 @@ string base64Encode(const string& s) {
   if (nbits) {
     res.push_back(base64Chars[data << (6 - nbits) & 0x3f]);
   }
-  while (res.size() % 4) res.push_back('=');
+  while (res.size() % 4) {
+    res.push_back('=');
+  }
 
   return res;
 }
@@ -1395,10 +1449,10 @@ static void signalHandlerThread(sigset_t set) {
     int signal = 0;
     sigwait(&set, &signal);
 
-    if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP)
+    if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP) {
       triggerInterrupt();
 
-    else if (signal == SIGWINCH) {
+    } else if (signal == SIGWINCH) {
       updateWindowSize();
     }
   }
@@ -1424,8 +1478,9 @@ static sigset_t savedSignalMask;
 void startSignalHandlerThread() {
   updateWindowSize();
 
-  if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask))
+  if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask)) {
     throw SysError("quering signal mask");
+  }
 
   sigset_t set;
   sigemptyset(&set);
@@ -1434,15 +1489,17 @@ void startSignalHandlerThread() {
   sigaddset(&set, SIGHUP);
   sigaddset(&set, SIGPIPE);
   sigaddset(&set, SIGWINCH);
-  if (pthread_sigmask(SIG_BLOCK, &set, nullptr))
+  if (pthread_sigmask(SIG_BLOCK, &set, nullptr)) {
     throw SysError("blocking signals");
+  }
 
   std::thread(signalHandlerThread, set).detach();
 }
 
 void restoreSignals() {
-  if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
+  if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) {
     throw SysError("restoring signals");
+  }
 }
 
 /* RAII helper to automatically deregister a callback. */
diff --git a/third_party/nix/src/libutil/xml-writer.cc b/third_party/nix/src/libutil/xml-writer.cc
index e07dd92f02..ed41286cc1 100644
--- a/third_party/nix/src/libutil/xml-writer.cc
+++ b/third_party/nix/src/libutil/xml-writer.cc
@@ -16,7 +16,9 @@ void XMLWriter::close() {
   if (closed) {
     return;
   }
-  while (!pendingElems.empty()) closeElement();
+  while (!pendingElems.empty()) {
+    closeElement();
+  }
   closed = true;
 }
 
@@ -68,20 +70,21 @@ void XMLWriter::writeAttrs(const XMLAttrs& attrs) {
     output << " " << i.first << "=\"";
     for (size_t j = 0; j < i.second.size(); ++j) {
       char c = i.second[j];
-      if (c == '"')
+      if (c == '"') {
         output << "&quot;";
-      else if (c == '<')
+      } else if (c == '<') {
         output << "&lt;";
-      else if (c == '>')
+      } else if (c == '>') {
         output << "&gt;";
-      else if (c == '&')
+      } else if (c == '&') {
         output << "&amp;";
-      /* Escape newlines to prevent attribute normalisation (see
-         XML spec, section 3.3.3. */
-      else if (c == '\n')
+        /* Escape newlines to prevent attribute normalisation (see
+           XML spec, section 3.3.3. */
+      } else if (c == '\n') {
         output << "&#xA;";
-      else
+      } else {
         output << c;
+      }
     }
     output << "\"";
   }
diff --git a/third_party/nix/src/nix-build/nix-build.cc b/third_party/nix/src/nix-build/nix-build.cc
index b5368a65db..bf20d50dbb 100644
--- a/third_party/nix/src/nix-build/nix-build.cc
+++ b/third_party/nix/src/nix-build/nix-build.cc
@@ -125,9 +125,11 @@ static void _main(int argc, char** argv) {
           line = chomp(line);
           std::smatch match;
           if (std::regex_match(line, match,
-                               std::regex("^#!\\s*nix-shell (.*)$")))
-            for (const auto& word : shellwords(match[1].str()))
+                               std::regex("^#!\\s*nix-shell (.*)$"))) {
+            for (const auto& word : shellwords(match[1].str())) {
               args.push_back(word);
+            }
+          }
         }
       }
     } catch (SysError&) {
@@ -145,63 +147,63 @@ static void _main(int argc, char** argv) {
           showManPage(myName);
         }
 
-        else if (*arg == "--version")
+        else if (*arg == "--version") {
           printVersion(myName);
 
-        else if (*arg == "--add-drv-link" || *arg == "--indirect")
+        } else if (*arg == "--add-drv-link" || *arg == "--indirect") {
           ;  // obsolete
 
-        else if (*arg == "--no-out-link" || *arg == "--no-link")
+        } else if (*arg == "--no-out-link" || *arg == "--no-link") {
           outLink = (Path)tmpDir + "/result";
 
-        else if (*arg == "--attr" || *arg == "-A")
+        } else if (*arg == "--attr" || *arg == "-A") {
           attrPaths.push_back(getArg(*arg, arg, end));
 
-        else if (*arg == "--drv-link")
+        } else if (*arg == "--drv-link") {
           getArg(*arg, arg, end);  // obsolete
 
-        else if (*arg == "--out-link" || *arg == "-o")
+        } else if (*arg == "--out-link" || *arg == "-o") {
           outLink = getArg(*arg, arg, end);
 
-        else if (*arg == "--add-root")
+        } else if (*arg == "--add-root") {
           gcRoot = getArg(*arg, arg, end);
 
-        else if (*arg == "--dry-run")
+        } else if (*arg == "--dry-run") {
           dryRun = true;
 
-        else if (*arg == "--repair") {
+        } else if (*arg == "--repair") {
           repair = Repair;
           buildMode = bmRepair;
         }
 
-        else if (*arg == "--run-env")  // obsolete
+        else if (*arg == "--run-env") {  // obsolete
           runEnv = true;
 
-        else if (*arg == "--command" || *arg == "--run") {
+        } else if (*arg == "--command" || *arg == "--run") {
           if (*arg == "--run") {
             interactive = false;
           }
           envCommand = getArg(*arg, arg, end) + "\nexit";
         }
 
-        else if (*arg == "--check")
+        else if (*arg == "--check") {
           buildMode = bmCheck;
 
-        else if (*arg == "--exclude")
+        } else if (*arg == "--exclude") {
           envExclude.push_back(getArg(*arg, arg, end));
 
-        else if (*arg == "--expr" || *arg == "-E")
+        } else if (*arg == "--expr" || *arg == "-E") {
           fromArgs = true;
 
-        else if (*arg == "--pure")
+        } else if (*arg == "--pure") {
           pure = true;
-        else if (*arg == "--impure")
+        } else if (*arg == "--impure") {
           pure = false;
 
-        else if (*arg == "--packages" || *arg == "-p")
+        } else if (*arg == "--packages" || *arg == "-p") {
           packages = true;
 
-        else if (inShebang && *arg == "-i") {
+        } else if (inShebang && *arg == "-i") {
           auto interpreter = getArg(*arg, arg, end);
           interactive = false;
           auto execArgs = "";
@@ -210,8 +212,9 @@ static void _main(int argc, char** argv) {
           // executes it unless it contains the string "perl" or "indir",
           // or (undocumented) argv[0] does not contain "perl". Exploit
           // the latter by doing "exec -a".
-          if (std::regex_search(interpreter, std::regex("perl")))
+          if (std::regex_search(interpreter, std::regex("perl"))) {
             execArgs = "-a PERL";
+          }
 
           std::ostringstream joined;
           for (const auto& i : savedArgs) {
@@ -233,17 +236,18 @@ static void _main(int argc, char** argv) {
           }
         }
 
-        else if (*arg == "--keep")
+        else if (*arg == "--keep") {
           keepVars.insert(getArg(*arg, arg, end));
 
-        else if (*arg == "-")
+        } else if (*arg == "-") {
           readStdin = true;
 
-        else if (*arg != "" && arg->at(0) == '-')
+        } else if (*arg != "" && arg->at(0) == '-') {
           return false;
 
-        else
+        } else {
           left.push_back(*arg);
+        }
 
         return true;
       });
@@ -252,8 +256,9 @@ static void _main(int argc, char** argv) {
 
   initPlugins();
 
-  if (packages && fromArgs)
+  if (packages && fromArgs) {
     throw UsageError("'-p' and '-E' are mutually exclusive");
+  }
 
   auto store = openStore();
 
@@ -290,22 +295,22 @@ static void _main(int argc, char** argv) {
   /* Parse the expressions. */
   std::vector<Expr*> exprs;
 
-  if (readStdin)
+  if (readStdin) {
     exprs = {state->parseStdin()};
-  else
+  } else {
     for (auto i : left) {
-      if (fromArgs)
+      if (fromArgs) {
         exprs.push_back(state->parseExprFromString(i, absPath(".")));
-      else {
+      } else {
         auto absolute = i;
         try {
           absolute = canonPath(absPath(i), true);
         } catch (Error& e) {
         };
         if (store->isStorePath(absolute) &&
-            std::regex_match(absolute, std::regex(".*\\.drv(!.*)?")))
+            std::regex_match(absolute, std::regex(".*\\.drv(!.*)?"))) {
           drvs.push_back(DrvInfo(*state, store, absolute));
-        else
+        } else {
           /* If we're in a #! script, interpret filenames
              relative to the script. */
           exprs.push_back(
@@ -313,8 +318,10 @@ static void _main(int argc, char** argv) {
                   lookupFileArg(*state, inShebang && !packages
                                             ? absPath(i, absPath(dirOf(script)))
                                             : i)))));
+        }
       }
     }
+  }
 
   /* Evaluate them into derivations. */
   if (attrPaths.empty()) {
@@ -342,9 +349,10 @@ static void _main(int argc, char** argv) {
     store->queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize,
                         narSize);
 
-    if (settings.printMissing)
+    if (settings.printMissing) {
       printMissing(ref<Store>(store), willBuild, willSubstitute, unknown,
                    downloadSize, narSize);
+    }
 
     if (!dryRun) {
       store->buildPaths(paths, buildMode);
@@ -352,8 +360,9 @@ static void _main(int argc, char** argv) {
   };
 
   if (runEnv) {
-    if (drvs.size() != 1)
+    if (drvs.size() != 1) {
       throw UsageError("nix-shell requires a single derivation");
+    }
 
     auto& drvInfo = drvs.front();
     auto drv = store->derivationFromPath(drvInfo.queryDrvPath());
@@ -374,10 +383,11 @@ static void _main(int argc, char** argv) {
         state->eval(expr, v);
 
         auto drv = getDerivation(*state, v, false);
-        if (!drv)
+        if (!drv) {
           throw Error(
               "the 'bashInteractive' attribute in <nixpkgs> did not evaluate "
               "to a derivation");
+        }
 
         pathsToBuild.insert(drv->queryDrvPath());
 
@@ -390,13 +400,15 @@ static void _main(int argc, char** argv) {
     }
 
     // Build or fetch all dependencies of the derivation.
-    for (const auto& input : drv.inputDrvs)
+    for (const auto& input : drv.inputDrvs) {
       if (std::all_of(envExclude.cbegin(), envExclude.cend(),
                       [&](const string& exclude) {
                         return !std::regex_search(input.first,
                                                   std::regex(exclude));
-                      }))
+                      })) {
         pathsToBuild.insert(makeDrvPathWithOutputs(input.first, input.second));
+      }
+    }
     for (const auto& src : drv.inputSrcs) {
       pathsToBuild.insert(src);
     }
@@ -414,10 +426,11 @@ static void _main(int argc, char** argv) {
 
     if (pure) {
       decltype(env) newEnv;
-      for (auto& i : env)
+      for (auto& i : env) {
         if (keepVars.count(i.first)) {
           newEnv.emplace(i);
         }
+      }
       env = newEnv;
       // NixOS hack: prevent /etc/bashrc from sourcing /etc/profile.
       env["__ETC_PROFILE_SOURCED"] = "1";
@@ -433,15 +446,17 @@ static void _main(int argc, char** argv) {
     bool keepTmp = false;
     int fileNr = 0;
 
-    for (auto& var : drv.env)
+    for (auto& var : drv.env) {
       if (passAsFile.count(var.first)) {
         keepTmp = true;
         string fn = ".attr-" + std::to_string(fileNr++);
         Path p = (Path)tmpDir + "/" + fn;
         writeFile(p, var.second);
         env[var.first + "Path"] = p;
-      } else
+      } else {
         env[var.first] = var.second;
+      }
+    }
 
     restoreAffinity();
 
@@ -507,16 +522,17 @@ static void _main(int argc, char** argv) {
       auto outPath = drvInfo.queryOutPath();
 
       auto outputName = drvInfo.queryOutputName();
-      if (outputName == "")
+      if (outputName == "") {
         throw Error("derivation '%s' lacks an 'outputName' attribute", drvPath);
+      }
 
       pathsToBuild.insert(drvPath + "!" + outputName);
 
       std::string drvPrefix;
       auto i = drvPrefixes.find(drvPath);
-      if (i != drvPrefixes.end())
+      if (i != drvPrefixes.end()) {
         drvPrefix = i->second;
-      else {
+      } else {
         drvPrefix = outLink;
         if (drvPrefixes.size()) {
           drvPrefix += fmt("-%d", drvPrefixes.size() + 1);
@@ -539,9 +555,11 @@ static void _main(int argc, char** argv) {
       return;
     }
 
-    for (auto& symlink : resultSymlinks)
-      if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>())
+    for (auto& symlink : resultSymlinks) {
+      if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) {
         store2->addPermRoot(symlink.second, absPath(symlink.first), true);
+      }
+    }
 
     for (auto& path : outPaths) {
       std::cout << path << '\n';
diff --git a/third_party/nix/src/nix-channel/nix-channel.cc b/third_party/nix/src/nix-channel/nix-channel.cc
index ec72258b10..ae5e77e86d 100644
--- a/third_party/nix/src/nix-channel/nix-channel.cc
+++ b/third_party/nix/src/nix-channel/nix-channel.cc
@@ -40,18 +40,22 @@ static void readChannels() {
 static void writeChannels() {
   auto channelsFD = AutoCloseFD{open(
       channelsList.c_str(), O_WRONLY | O_CLOEXEC | O_CREAT | O_TRUNC, 0644)};
-  if (!channelsFD)
+  if (!channelsFD) {
     throw SysError(format("opening '%1%' for writing") % channelsList);
-  for (const auto& channel : channels)
+  }
+  for (const auto& channel : channels) {
     writeFull(channelsFD.get(), channel.second + " " + channel.first + "\n");
+  }
 }
 
 // Adds a channel.
 static void addChannel(const string& url, const string& name) {
-  if (!regex_search(url, std::regex("^(file|http|https)://")))
+  if (!regex_search(url, std::regex("^(file|http|https)://"))) {
     throw Error(format("invalid channel URL '%1%'") % url);
-  if (!regex_search(name, std::regex("^[a-zA-Z0-9_][a-zA-Z0-9_\\.-]*$")))
+  }
+  if (!regex_search(name, std::regex("^[a-zA-Z0-9_][a-zA-Z0-9_\\.-]*$"))) {
     throw Error(format("invalid channel identifier '%1%'") % name);
+  }
   readChannels();
   channels[name] = url;
   writeChannels();
@@ -157,10 +161,12 @@ static void update(const StringSet& channelNames) {
   // Make the channels appear in nix-env.
   struct stat st;
   if (lstat(nixDefExpr.c_str(), &st) == 0) {
-    if (S_ISLNK(st.st_mode))
+    if (S_ISLNK(st.st_mode)) {
       // old-skool ~/.nix-defexpr
-      if (unlink(nixDefExpr.c_str()) == -1)
+      if (unlink(nixDefExpr.c_str()) == -1) {
         throw SysError(format("unlinking %1%") % nixDefExpr);
+      }
+    }
   } else if (errno != ENOENT) {
     throw SysError(format("getting status of %1%") % nixDefExpr);
   }
@@ -210,8 +216,9 @@ static int _main(int argc, char** argv) {
       case cNone:
         throw UsageError("no command specified");
       case cAdd:
-        if (args.size() < 1 || args.size() > 2)
+        if (args.size() < 1 || args.size() > 2) {
           throw UsageError("'--add' requires one or two arguments");
+        }
         {
           auto url = args[0];
           std::string name;
@@ -226,8 +233,9 @@ static int _main(int argc, char** argv) {
         }
         break;
       case cRemove:
-        if (args.size() != 1)
+        if (args.size() != 1) {
           throw UsageError("'--remove' requires one argument");
+        }
         removeChannel(args[0]);
         break;
       case cList:
@@ -235,15 +243,17 @@ static int _main(int argc, char** argv) {
           throw UsageError("'--list' expects no arguments");
         }
         readChannels();
-        for (const auto& channel : channels)
+        for (const auto& channel : channels) {
           std::cout << channel.first << ' ' << channel.second << '\n';
+        }
         break;
       case cUpdate:
         update(StringSet(args.begin(), args.end()));
         break;
       case cRollback:
-        if (args.size() > 1)
+        if (args.size() > 1) {
           throw UsageError("'--rollback' has at most one argument");
+        }
         Strings envArgs{"--profile", profile};
         if (args.size() == 1) {
           envArgs.push_back("--switch-generation");
diff --git a/third_party/nix/src/nix-collect-garbage/nix-collect-garbage.cc b/third_party/nix/src/nix-collect-garbage/nix-collect-garbage.cc
index 1b20386ff1..29c68e9637 100644
--- a/third_party/nix/src/nix-collect-garbage/nix-collect-garbage.cc
+++ b/third_party/nix/src/nix-collect-garbage/nix-collect-garbage.cc
@@ -42,10 +42,11 @@ void removeOldGenerations(std::string dir) {
       }
       if (link.find("link") != string::npos) {
         LOG(INFO) << "removing old generations of profile " << path;
-        if (deleteOlderThan != "")
+        if (deleteOlderThan != "") {
           deleteGenerationsOlderThan(path, deleteOlderThan, dryRun);
-        else
+        } else {
           deleteOldGenerations(path, dryRun);
+        }
       }
     } else if (type == DT_DIR) {
       removeOldGenerations(path);
@@ -61,22 +62,23 @@ static int _main(int argc, char** argv) {
 
     parseCmdLine(
         argc, argv, [&](Strings::iterator& arg, const Strings::iterator& end) {
-          if (*arg == "--help")
+          if (*arg == "--help") {
             showManPage("nix-collect-garbage");
-          else if (*arg == "--version")
+          } else if (*arg == "--version") {
             printVersion("nix-collect-garbage");
-          else if (*arg == "--delete-old" || *arg == "-d")
+          } else if (*arg == "--delete-old" || *arg == "-d") {
             removeOld = true;
-          else if (*arg == "--delete-older-than") {
+          } else if (*arg == "--delete-older-than") {
             removeOld = true;
             deleteOlderThan = getArg(*arg, arg, end);
-          } else if (*arg == "--dry-run")
+          } else if (*arg == "--dry-run") {
             dryRun = true;
-          else if (*arg == "--max-freed") {
+          } else if (*arg == "--max-freed") {
             long long maxFreed = getIntArg<long long>(*arg, arg, end, true);
             options.maxFreed = maxFreed >= 0 ? maxFreed : 0;
-          } else
+          } else {
             return false;
+          }
           return true;
         });
 
diff --git a/third_party/nix/src/nix-copy-closure/nix-copy-closure.cc b/third_party/nix/src/nix-copy-closure/nix-copy-closure.cc
index 2ec6a02136..67765a8cf7 100644
--- a/third_party/nix/src/nix-copy-closure/nix-copy-closure.cc
+++ b/third_party/nix/src/nix-copy-closure/nix-copy-closure.cc
@@ -18,32 +18,33 @@ static int _main(int argc, char** argv) {
 
     parseCmdLine(
         argc, argv, [&](Strings::iterator& arg, const Strings::iterator& end) {
-          if (*arg == "--help")
+          if (*arg == "--help") {
             showManPage("nix-copy-closure");
-          else if (*arg == "--version")
+          } else if (*arg == "--version") {
             printVersion("nix-copy-closure");
-          else if (*arg == "--gzip" || *arg == "--bzip2" || *arg == "--xz") {
+          } else if (*arg == "--gzip" || *arg == "--bzip2" || *arg == "--xz") {
             if (*arg != "--gzip") {
               LOG(WARNING) << "'" << *arg
                            << "' is not implemented, falling back to gzip";
             }
             gzip = true;
-          } else if (*arg == "--from")
+          } else if (*arg == "--from") {
             toMode = false;
-          else if (*arg == "--to")
+          } else if (*arg == "--to") {
             toMode = true;
-          else if (*arg == "--include-outputs")
+          } else if (*arg == "--include-outputs") {
             includeOutputs = true;
-          else if (*arg == "--show-progress")
+          } else if (*arg == "--show-progress") {
             LOG(WARNING) << "'--show-progress' is not implemented";
-          else if (*arg == "--dry-run")
+          } else if (*arg == "--dry-run") {
             dryRun = true;
-          else if (*arg == "--use-substitutes" || *arg == "-s")
+          } else if (*arg == "--use-substitutes" || *arg == "-s") {
             useSubstitutes = Substitute;
-          else if (sshHost.empty())
+          } else if (sshHost.empty()) {
             sshHost = *arg;
-          else
+          } else {
             storePaths.insert(*arg);
+          }
           return true;
         });
 
@@ -58,8 +59,9 @@ static int _main(int argc, char** argv) {
     auto from = toMode ? openStore() : openStore(remoteUri);
 
     PathSet storePaths2;
-    for (auto& path : storePaths)
+    for (auto& path : storePaths) {
       storePaths2.insert(from->followLinksToStorePath(path));
+    }
 
     PathSet closure;
     from->computeFSClosure(storePaths2, closure, false, includeOutputs);
diff --git a/third_party/nix/src/nix-daemon/nix-daemon.cc b/third_party/nix/src/nix-daemon/nix-daemon.cc
index 34ea932fe9..4f71a0c36f 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon.cc
@@ -90,8 +90,9 @@ struct TunnelLogger {
         state->canSendStderr = false;
         throw;
       }
-    } else
+    } else {
       state->pendingMsgs.push_back(s);
+    }
   }
 
   void log(const FormatOrString& fs) {
@@ -253,14 +254,15 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
       Path path = readStorePath(*store, from);
       logger->startWork();
       PathSet paths;
-      if (op == wopQueryReferences)
+      if (op == wopQueryReferences) {
         paths = store->queryPathInfo(path)->references;
-      else if (op == wopQueryReferrers)
+      } else if (op == wopQueryReferrers) {
         store->queryReferrers(path, paths);
-      else if (op == wopQueryValidDerivers)
+      } else if (op == wopQueryValidDerivers) {
         paths = store->queryValidDerivers(path);
-      else
+      } else {
         paths = store->queryDerivationOutputs(path);
+      }
       logger->stopWork();
       to << paths;
       break;
@@ -377,10 +379,11 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
 
         /* Repairing is not atomic, so disallowed for "untrusted"
            clients.  */
-        if (mode == bmRepair && !trusted)
+        if (mode == bmRepair && !trusted) {
           throw Error(
               "repairing is not allowed because you are not in "
               "'trusted-users'");
+        }
       }
       logger->startWork();
       store->buildPaths(drvs, mode);
@@ -451,10 +454,11 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
 
       to << size;
 
-      for (auto& [target, links] : roots)
+      for (auto& [target, links] : roots) {
         for (auto& link : links) {
           to << link << target;
         }
+      }
 
       break;
     }
@@ -472,8 +476,9 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
       GCResults results;
 
       logger->startWork();
-      if (options.ignoreLiveness)
+      if (options.ignoreLiveness) {
         throw Error("you are not allowed to ignore liveness");
+      }
       store->collectGarbage(options, results);
       logger->stopWork();
 
@@ -522,30 +527,33 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
           }
           Strings subs;
           auto ss = tokenizeString<Strings>(value);
-          for (auto& s : ss)
-            if (trusted.count(s))
+          for (auto& s : ss) {
+            if (trusted.count(s)) {
               subs.push_back(s);
-            else
+            } else {
               LOG(WARNING) << "ignoring untrusted substituter '" << s << "'";
+            }
+          }
           res = subs;
           return true;
         };
 
         try {
-          if (name == "ssh-auth-sock")  // obsolete
+          if (name == "ssh-auth-sock") {  // obsolete
             ;
-          else if (trusted || name == settings.buildTimeout.name ||
-                   name == "connect-timeout" ||
-                   (name == "builders" && value == ""))
+          } else if (trusted || name == settings.buildTimeout.name ||
+                     name == "connect-timeout" ||
+                     (name == "builders" && value == "")) {
             settings.set(name, value);
-          else if (setSubstituters(settings.substituters))
+          } else if (setSubstituters(settings.substituters)) {
             ;
-          else if (setSubstituters(settings.extraSubstituters))
+          } else if (setSubstituters(settings.extraSubstituters)) {
             ;
-          else
+          } else {
             LOG(WARNING) << "ignoring the user-specified setting '" << name
                          << "', because it is a "
                          << "restricted setting and you are not a trusted user";
+          }
         } catch (UsageError& e) {
           LOG(WARNING) << e.what();
         }
@@ -562,9 +570,9 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
       store->querySubstitutablePathInfos({path}, infos);
       logger->stopWork();
       SubstitutablePathInfos::iterator i = infos.find(path);
-      if (i == infos.end())
+      if (i == infos.end()) {
         to << 0;
-      else {
+      } else {
         to << 1 << i->second.deriver << i->second.references
            << i->second.downloadSize << i->second.narSize;
       }
@@ -632,8 +640,9 @@ static void performOp(TunnelLogger* logger, ref<Store> store, bool trusted,
       bool checkContents, repair;
       from >> checkContents >> repair;
       logger->startWork();
-      if (repair && !trusted)
+      if (repair && !trusted) {
         throw Error("you are not privileged to repair paths");
+      }
       bool errors = store->verifyStore(checkContents, (RepairFlag)repair);
       logger->stopWork();
       to << errors;
@@ -746,8 +755,9 @@ static void processConnection(bool trusted, const std::string& userName,
     DLOG(INFO) << opCount << " operations";
   });
 
-  if (GET_PROTOCOL_MINOR(clientVersion) >= 14 && readInt(from))
+  if (GET_PROTOCOL_MINOR(clientVersion) >= 14 && readInt(from)) {
     setAffinityTo(readInt(from));
+  }
 
   readInt(from);  // obsolete reserveSpace
 
@@ -823,8 +833,9 @@ static void sigChldHandler(int sigNo) {
   // Ensure we don't modify errno of whatever we've interrupted
   auto saved_errno = errno;
   /* Reap all dead children. */
-  while (waitpid(-1, 0, WNOHANG) > 0)
+  while (waitpid(-1, 0, WNOHANG) > 0) {
     ;
+  }
   errno = saved_errno;
 }
 
@@ -833,8 +844,9 @@ static void setSigChldAction(bool autoReap) {
   act.sa_handler = autoReap ? sigChldHandler : SIG_DFL;
   sigfillset(&act.sa_mask);
   act.sa_flags = 0;
-  if (sigaction(SIGCHLD, &act, &oact))
+  if (sigaction(SIGCHLD, &act, &oact)) {
     throw SysError("setting SIGCHLD handler");
+  }
 }
 
 bool matchUser(const string& user, const string& group, const Strings& users) {
@@ -846,7 +858,7 @@ bool matchUser(const string& user, const string& group, const Strings& users) {
     return true;
   }
 
-  for (auto& i : users)
+  for (auto& i : users) {
     if (string(i, 0, 1) == "@") {
       if (group == string(i, 1)) {
         return true;
@@ -855,11 +867,13 @@ bool matchUser(const string& user, const string& group, const Strings& users) {
       if (!gr) {
         continue;
       }
-      for (char** mem = gr->gr_mem; *mem; mem++)
+      for (char** mem = gr->gr_mem; *mem; mem++) {
         if (user == string(*mem)) {
           return true;
         }
+      }
     }
+  }
 
   return false;
 }
@@ -881,8 +895,9 @@ static PeerInfo getPeerInfo(int remote) {
 
   ucred cred;
   socklen_t credLen = sizeof(cred);
-  if (getsockopt(remote, SOL_SOCKET, SO_PEERCRED, &cred, &credLen) == -1)
+  if (getsockopt(remote, SOL_SOCKET, SO_PEERCRED, &cred, &credLen) == -1) {
     throw SysError("getting peer credentials");
+  }
   peer = {true, cred.pid, true, cred.uid, true, cred.gid};
 
 #elif defined(LOCAL_PEERCRED)
@@ -918,8 +933,9 @@ static void daemonLoop(char** argv) {
   /* Handle socket-based activation by systemd. */
   if (getEnv("LISTEN_FDS") != "") {
     if (getEnv("LISTEN_PID") != std::to_string(getpid()) ||
-        getEnv("LISTEN_FDS") != "1")
+        getEnv("LISTEN_FDS") != "1") {
       throw Error("unexpected systemd environment variables");
+    }
     fdSocket = SD_LISTEN_FDS_START;
   }
 
@@ -938,14 +954,16 @@ static void daemonLoop(char** argv) {
     /* Urgh, sockaddr_un allows path names of only 108 characters.
        So chdir to the socket directory so that we can pass a
        relative path name. */
-    if (chdir(dirOf(socketPath).c_str()) == -1)
+    if (chdir(dirOf(socketPath).c_str()) == -1) {
       throw SysError("cannot change current directory");
+    }
     Path socketPathRel = "./" + baseNameOf(socketPath);
 
     struct sockaddr_un addr;
     addr.sun_family = AF_UNIX;
-    if (socketPathRel.size() >= sizeof(addr.sun_path))
+    if (socketPathRel.size() >= sizeof(addr.sun_path)) {
       throw Error(format("socket path '%1%' is too long") % socketPathRel);
+    }
     strcpy(addr.sun_path, socketPathRel.c_str());
 
     unlink(socketPath.c_str());
@@ -956,14 +974,17 @@ static void daemonLoop(char** argv) {
     mode_t oldMode = umask(0111);
     int res = bind(fdSocket.get(), (struct sockaddr*)&addr, sizeof(addr));
     umask(oldMode);
-    if (res == -1)
+    if (res == -1) {
       throw SysError(format("cannot bind to socket '%1%'") % socketPath);
+    }
 
-    if (chdir("/") == -1) /* back to the root */
+    if (chdir("/") == -1) { /* back to the root */
       throw SysError("cannot change current directory");
+    }
 
-    if (listen(fdSocket.get(), 5) == -1)
+    if (listen(fdSocket.get(), 5) == -1) {
       throw SysError(format("cannot listen on socket '%1%'") % socketPath);
+    }
   }
 
   closeOnExec(fdSocket.get());
@@ -1062,16 +1083,17 @@ static int _main(int argc, char** argv) {
 
     parseCmdLine(argc, argv,
                  [&](Strings::iterator& arg, const Strings::iterator& end) {
-                   if (*arg == "--daemon")
+                   if (*arg == "--daemon") {
                      ; /* ignored for backwards compatibility */
-                   else if (*arg == "--help")
+                   } else if (*arg == "--help") {
                      showManPage("nix-daemon");
-                   else if (*arg == "--version")
+                   } else if (*arg == "--version") {
                      printVersion("nix-daemon");
-                   else if (*arg == "--stdio")
+                   } else if (*arg == "--stdio") {
                      stdio = true;
-                   else
+                   } else {
                      return false;
+                   }
                    return true;
                  });
 
@@ -1087,20 +1109,23 @@ static int _main(int argc, char** argv) {
         }
 
         auto socketDir = dirOf(socketPath);
-        if (chdir(socketDir.c_str()) == -1)
+        if (chdir(socketDir.c_str()) == -1) {
           throw SysError(format("changing to socket directory '%1%'") %
                          socketDir);
+        }
 
         auto socketName = baseNameOf(socketPath);
         auto addr = sockaddr_un{};
         addr.sun_family = AF_UNIX;
-        if (socketName.size() + 1 >= sizeof(addr.sun_path))
+        if (socketName.size() + 1 >= sizeof(addr.sun_path)) {
           throw Error(format("socket name %1% is too long") % socketName);
+        }
         strcpy(addr.sun_path, socketName.c_str());
 
-        if (connect(s, (struct sockaddr*)&addr, sizeof(addr)) == -1)
+        if (connect(s, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
           throw SysError(format("cannot connect to daemon at %1%") %
                          socketPath);
+        }
 
         auto nfds = (s > STDIN_FILENO ? s : STDIN_FILENO) + 1;
         while (true) {
@@ -1108,23 +1133,26 @@ static int _main(int argc, char** argv) {
           FD_ZERO(&fds);
           FD_SET(s, &fds);
           FD_SET(STDIN_FILENO, &fds);
-          if (select(nfds, &fds, nullptr, nullptr, nullptr) == -1)
+          if (select(nfds, &fds, nullptr, nullptr, nullptr) == -1) {
             throw SysError("waiting for data from client or server");
+          }
           if (FD_ISSET(s, &fds)) {
             auto res = splice(s, nullptr, STDOUT_FILENO, nullptr, SSIZE_MAX,
                               SPLICE_F_MOVE);
-            if (res == -1)
+            if (res == -1) {
               throw SysError("splicing data from daemon socket to stdout");
-            else if (res == 0)
+            } else if (res == 0) {
               throw EndOfFile("unexpected EOF from daemon socket");
+            }
           }
           if (FD_ISSET(STDIN_FILENO, &fds)) {
             auto res = splice(STDIN_FILENO, nullptr, s, nullptr, SSIZE_MAX,
                               SPLICE_F_MOVE);
-            if (res == -1)
+            if (res == -1) {
               throw SysError("splicing data from stdin to daemon socket");
-            else if (res == 0)
+            } else if (res == 0) {
               return 0;
+            }
           }
         }
       } else {
diff --git a/third_party/nix/src/nix-env/nix-env.cc b/third_party/nix/src/nix-env/nix-env.cc
index 5aa0a7d57e..2a4f94bfaf 100644
--- a/third_party/nix/src/nix-env/nix-env.cc
+++ b/third_party/nix/src/nix-env/nix-env.cc
@@ -60,22 +60,24 @@ struct Globals {
 typedef void (*Operation)(Globals& globals, Strings opFlags, Strings opArgs);
 
 static string needArg(Strings::iterator& i, Strings& args, const string& arg) {
-  if (i == args.end())
+  if (i == args.end()) {
     throw UsageError(format("'%1%' requires an argument") % arg);
+  }
   return *i++;
 }
 
 static bool parseInstallSourceOptions(Globals& globals, Strings::iterator& i,
                                       Strings& args, const string& arg) {
-  if (arg == "--from-expression" || arg == "-E")
+  if (arg == "--from-expression" || arg == "-E") {
     globals.instSource.type = srcNixExprs;
-  else if (arg == "--from-profile") {
+  } else if (arg == "--from-profile") {
     globals.instSource.type = srcProfile;
     globals.instSource.profile = needArg(i, args, arg);
-  } else if (arg == "--attr" || arg == "-A")
+  } else if (arg == "--attr" || arg == "-A") {
     globals.instSource.type = srcAttrPath;
-  else
+  } else {
     return false;
+  }
   return true;
 }
 
@@ -102,8 +104,9 @@ static void getAllExprs(EvalState& state, const Path& path, StringSet& attrs,
     Path path2 = path + "/" + i;
 
     struct stat st;
-    if (stat(path2.c_str(), &st) == -1)
+    if (stat(path2.c_str(), &st) == -1) {
       continue;  // ignore dangling symlinks in ~/.nix-defexpr
+    }
 
     if (isNixExpr(path2, st) &&
         (!S_ISREG(st.st_mode) || hasSuffix(path2, ".nix"))) {
@@ -112,8 +115,9 @@ static void getAllExprs(EvalState& state, const Path& path, StringSet& attrs,
          `-A' option.  Useful if you want to stick a Nix
          expression directly in ~/.nix-defexpr. */
       string attrName = i;
-      if (hasSuffix(attrName, ".nix"))
+      if (hasSuffix(attrName, ".nix")) {
         attrName = string(attrName, 0, attrName.size() - 4);
+      }
       if (attrs.find(attrName) != attrs.end()) {
         LOG(WARNING) << "name collision in input Nix expressions, skipping '"
                      << path2 << "'";
@@ -124,21 +128,24 @@ static void getAllExprs(EvalState& state, const Path& path, StringSet& attrs,
       Value& vFun = state.getBuiltin("import");
       Value& vArg(*state.allocValue());
       mkString(vArg, path2);
-      if (v.attrs->size() == v.attrs->capacity())
+      if (v.attrs->size() == v.attrs->capacity()) {
         throw Error(format("too many Nix expressions in directory '%1%'") %
                     path);
+      }
       mkApp(*state.allocAttr(v, state.symbols.create(attrName)), vFun, vArg);
-    } else if (S_ISDIR(st.st_mode))
+    } else if (S_ISDIR(st.st_mode)) {
       /* `path2' is a directory (with no default.nix in it);
          recurse into it. */
       getAllExprs(state, path2, attrs, v);
+    }
   }
 }
 
 static void loadSourceExpr(EvalState& state, const Path& path, Value& v) {
   struct stat st;
-  if (stat(path.c_str(), &st) == -1)
+  if (stat(path.c_str(), &st) == -1) {
     throw SysError(format("getting information about '%1%'") % path);
+  }
 
   if (isNixExpr(path, st)) {
     state.evalFile(path, v);
@@ -159,8 +166,9 @@ static void loadSourceExpr(EvalState& state, const Path& path, Value& v) {
     v.attrs->sort();
   }
 
-  else
+  else {
     throw Error("path '%s' is not a directory or a Nix expression", path);
+  }
 }
 
 static void loadDerivations(EvalState& state, Path nixExprPath,
@@ -205,9 +213,11 @@ static bool isPrebuilt(EvalState& state, DrvInfo& elem) {
 
 static void checkSelectorUse(DrvNames& selectors) {
   /* Check that all selectors have been used. */
-  for (auto& i : selectors)
-    if (i.hits == 0 && i.fullName != "*")
+  for (auto& i : selectors) {
+    if (i.hits == 0 && i.fullName != "*") {
       throw Error(format("selector '%1%' matches no derivations") % i.fullName);
+    }
+  }
 }
 
 static DrvInfos filterBySelector(EvalState& state, const DrvInfos& allElems,
@@ -263,9 +273,10 @@ static DrvInfos filterBySelector(EvalState& state, const DrvInfos& allElems,
           if (d == 0) {
             d = comparePriorities(state, j.first, k->second.first);
           }
-          if (d == 0)
+          if (d == 0) {
             d = compareVersions(drvName.version,
                                 DrvName(k->second.first.queryName()).version);
+          }
         }
 
         if (d > 0) {
@@ -279,21 +290,23 @@ static DrvInfos filterBySelector(EvalState& state, const DrvInfos& allElems,
 
       matches.clear();
       for (auto& j : newest) {
-        if (multiple.find(j.second.first.queryName()) != multiple.end())
+        if (multiple.find(j.second.first.queryName()) != multiple.end()) {
           LOG(WARNING) << "warning: there are multiple derivations named '"
                        << j.second.first.queryName()
                        << "'; using the first one";
+        }
         matches.push_back(j.second);
       }
     }
 
     /* Insert only those elements in the final list that we
        haven't inserted before. */
-    for (auto& j : matches)
+    for (auto& j : matches) {
       if (done.find(j.second) == done.end()) {
         done.insert(j.second);
         elems.push_back(j.first);
       }
+    }
   }
 
   checkSelectorUse(selectors);
@@ -307,8 +320,9 @@ static void queryInstSources(EvalState& state, InstallSourceInfo& instSource,
                              const Strings& args, DrvInfos& elems,
                              bool newestOnly) {
   InstallSourceType type = instSource.type;
-  if (type == srcUnknown && args.size() > 0 && isPath(args.front()))
+  if (type == srcUnknown && args.size() > 0 && isPath(args.front())) {
     type = srcStorePaths;
+  }
 
   switch (type) {
     /* Get the available user environment elements from the
@@ -369,10 +383,12 @@ static void queryInstSources(EvalState& state, InstallSourceInfo& instSource,
           elem.setOutPath(
               state.store->derivationFromPath(path).findOutput("out"));
           if (name.size() >= drvExtension.size() &&
-              string(name, name.size() - drvExtension.size()) == drvExtension)
+              string(name, name.size() - drvExtension.size()) == drvExtension) {
             name = string(name, 0, name.size() - drvExtension.size());
-        } else
+          }
+        } else {
           elem.setOutPath(path);
+        }
 
         elems.push_back(elem);
       }
@@ -405,10 +421,11 @@ static void printMissing(EvalState& state, DrvInfos& elems) {
   PathSet targets;
   for (auto& i : elems) {
     Path drvPath = i.queryDrvPath();
-    if (drvPath != "")
+    if (drvPath != "") {
       targets.insert(drvPath);
-    else
+    } else {
       targets.insert(i.queryOutPath());
+    }
   }
 
   printMissing(state.store, targets);
@@ -425,9 +442,11 @@ static void installDerivations(Globals& globals, const Strings& args,
   queryInstSources(*globals.state, globals.instSource, args, newElemsTmp, true);
 
   /* If --prebuilt-only is given, filter out source-only packages. */
-  for (auto& i : newElemsTmp)
-    if (!globals.prebuiltOnly || isPrebuilt(*globals.state, i))
+  for (auto& i : newElemsTmp) {
+    if (!globals.prebuiltOnly || isPrebuilt(*globals.state, i)) {
       newElems.push_back(i);
+    }
+  }
 
   StringSet newNames;
   for (auto& i : newElems) {
@@ -454,10 +473,11 @@ static void installDerivations(Globals& globals, const Strings& args,
       for (auto& i : installedElems) {
         DrvName drvName(i.queryName());
         if (!globals.preserveInstalled &&
-            newNames.find(drvName.name) != newNames.end() && !keep(i))
+            newNames.find(drvName.name) != newNames.end() && !keep(i)) {
           LOG(INFO) << "replacing old '" << i.queryName() << "'";
-        else
+        } else {
           allElems.push_back(i);
+        }
       }
 
       for (auto& i : newElems) {
@@ -472,22 +492,24 @@ static void installDerivations(Globals& globals, const Strings& args,
     }
 
     if (createUserEnv(*globals.state, allElems, profile,
-                      settings.envKeepDerivations, lockToken))
+                      settings.envKeepDerivations, lockToken)) {
       break;
+    }
   }
 }
 
 static void opInstall(Globals& globals, Strings opFlags, Strings opArgs) {
   for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
     string arg = *i++;
-    if (parseInstallSourceOptions(globals, i, opFlags, arg))
+    if (parseInstallSourceOptions(globals, i, opFlags, arg)) {
       ;
-    else if (arg == "--preserve-installed" || arg == "-P")
+    } else if (arg == "--preserve-installed" || arg == "-P") {
       globals.preserveInstalled = true;
-    else if (arg == "--remove-all" || arg == "-r")
+    } else if (arg == "--remove-all" || arg == "-r") {
       globals.removeAll = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % arg);
+    }
   }
 
   installDerivations(globals, opArgs, globals.profile);
@@ -569,8 +591,9 @@ static void upgradeDerivations(Globals& globals, const Strings& args,
           LOG(INFO) << action << " '" << i.queryName() << "' to '"
                     << bestElem->queryName() << "'";
           newElems.push_back(*bestElem);
-        } else
+        } else {
           newElems.push_back(i);
+        }
 
       } catch (Error& e) {
         e.addPrefix(
@@ -586,8 +609,9 @@ static void upgradeDerivations(Globals& globals, const Strings& args,
     }
 
     if (createUserEnv(*globals.state, newElems, globals.profile,
-                      settings.envKeepDerivations, lockToken))
+                      settings.envKeepDerivations, lockToken)) {
       break;
+    }
   }
 }
 
@@ -595,18 +619,19 @@ static void opUpgrade(Globals& globals, Strings opFlags, Strings opArgs) {
   UpgradeType upgradeType = utLt;
   for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
     string arg = *i++;
-    if (parseInstallSourceOptions(globals, i, opFlags, arg))
+    if (parseInstallSourceOptions(globals, i, opFlags, arg)) {
       ;
-    else if (arg == "--lt")
+    } else if (arg == "--lt") {
       upgradeType = utLt;
-    else if (arg == "--leq")
+    } else if (arg == "--leq") {
       upgradeType = utLeq;
-    else if (arg == "--eq")
+    } else if (arg == "--eq") {
       upgradeType = utEq;
-    else if (arg == "--always")
+    } else if (arg == "--always") {
       upgradeType = utAlways;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % arg);
+    }
   }
 
   upgradeDerivations(globals, opArgs, upgradeType);
@@ -620,10 +645,12 @@ static void setMetaFlag(EvalState& state, DrvInfo& drv, const string& name,
 }
 
 static void opSetFlag(Globals& globals, Strings opFlags, Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-  if (opArgs.size() < 2)
+  }
+  if (opArgs.size() < 2) {
     throw UsageError("not enough arguments to '--set-flag'");
+  }
 
   Strings::iterator arg = opArgs.begin();
   string flagName = *arg++;
@@ -638,21 +665,23 @@ static void opSetFlag(Globals& globals, Strings opFlags, Strings opArgs) {
     /* Update all matching derivations. */
     for (auto& i : installedElems) {
       DrvName drvName(i.queryName());
-      for (auto& j : selectors)
+      for (auto& j : selectors) {
         if (j.matches(drvName)) {
           LOG(INFO) << "setting flag on '" << i.queryName() << "'";
           j.hits++;
           setMetaFlag(*globals.state, i, flagName, flagValue);
           break;
         }
+      }
     }
 
     checkSelectorUse(selectors);
 
     /* Write the new user environment. */
     if (createUserEnv(*globals.state, installedElems, globals.profile,
-                      settings.envKeepDerivations, lockToken))
+                      settings.envKeepDerivations, lockToken)) {
       break;
+    }
   }
 }
 
@@ -664,10 +693,11 @@ static void opSet(Globals& globals, Strings opFlags, Strings opArgs) {
 
   for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
     string arg = *i++;
-    if (parseInstallSourceOptions(globals, i, opFlags, arg))
+    if (parseInstallSourceOptions(globals, i, opFlags, arg)) {
       ;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % arg);
+    }
   }
 
   DrvInfos elems;
@@ -716,7 +746,7 @@ static void uninstallDerivations(Globals& globals, Strings& selectors,
     for (auto& i : installedElems) {
       DrvName drvName(i.queryName());
       bool found = false;
-      for (auto& j : selectors)
+      for (auto& j : selectors) {
         /* !!! the repeated calls to followLinksToStorePath()
            are expensive, should pre-compute them. */
         if ((isPath(j) &&
@@ -727,6 +757,7 @@ static void uninstallDerivations(Globals& globals, Strings& selectors,
           found = true;
           break;
         }
+      }
       if (!found) {
         newElems.push_back(i);
       }
@@ -737,14 +768,16 @@ static void uninstallDerivations(Globals& globals, Strings& selectors,
     }
 
     if (createUserEnv(*globals.state, newElems, profile,
-                      settings.envKeepDerivations, lockToken))
+                      settings.envKeepDerivations, lockToken)) {
       break;
+    }
   }
 }
 
 static void opUninstall(Globals& globals, Strings opFlags, Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  }
   uninstallDerivations(globals, opArgs, globals.profile);
 }
 
@@ -769,10 +802,11 @@ void printTable(Table& table) {
     assert(i.size() == nrColumns);
     Strings::iterator j;
     size_t column;
-    for (j = i.begin(), column = 0; j != i.end(); ++j, ++column)
+    for (j = i.begin(), column = 0; j != i.end(); ++j, ++column) {
       if (j->size() > widths[column]) {
         widths[column] = j->size();
       }
+    }
   }
 
   for (auto& i : table) {
@@ -782,8 +816,9 @@ void printTable(Table& table) {
       string s = *j;
       replace(s.begin(), s.end(), '\n', ' ');
       cout << s;
-      if (column < nrColumns - 1)
+      if (column < nrColumns - 1) {
         cout << string(widths[column] - s.size() + 2, ' ');
+      }
     }
     cout << std::endl;
   }
@@ -818,8 +853,9 @@ static VersionDiff compareVersionAgainstSet(const DrvInfo& elem,
         version = name2.version;
       } else if (diff != cvGreater && diff != cvEqual && d > 0) {
         diff = cvLess;
-        if (version == "" || compareVersions(version, name2.version) < 0)
+        if (version == "" || compareVersions(version, name2.version) < 0) {
           version = name2.version;
+        }
       }
     }
   }
@@ -877,48 +913,51 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
 
   for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
     string arg = *i++;
-    if (arg == "--status" || arg == "-s")
+    if (arg == "--status" || arg == "-s") {
       printStatus = true;
-    else if (arg == "--no-name")
+    } else if (arg == "--no-name") {
       printName = false;
-    else if (arg == "--system")
+    } else if (arg == "--system") {
       printSystem = true;
-    else if (arg == "--description")
+    } else if (arg == "--description") {
       printDescription = true;
-    else if (arg == "--compare-versions" || arg == "-c")
+    } else if (arg == "--compare-versions" || arg == "-c") {
       compareVersions = true;
-    else if (arg == "--drv-path")
+    } else if (arg == "--drv-path") {
       printDrvPath = true;
-    else if (arg == "--out-path")
+    } else if (arg == "--out-path") {
       printOutPath = true;
-    else if (arg == "--meta")
+    } else if (arg == "--meta") {
       printMeta = true;
-    else if (arg == "--installed")
+    } else if (arg == "--installed") {
       source = sInstalled;
-    else if (arg == "--available" || arg == "-a")
+    } else if (arg == "--available" || arg == "-a") {
       source = sAvailable;
-    else if (arg == "--xml")
+    } else if (arg == "--xml") {
       xmlOutput = true;
-    else if (arg == "--json")
+    } else if (arg == "--json") {
       jsonOutput = true;
-    else if (arg == "--attr-path" || arg == "-P")
+    } else if (arg == "--attr-path" || arg == "-P") {
       printAttrPath = true;
-    else if (arg == "--attr" || arg == "-A")
+    } else if (arg == "--attr" || arg == "-A") {
       attrPath = needArg(i, opFlags, arg);
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % arg);
+    }
   }
 
   /* Obtain derivation information from the specified source. */
   DrvInfos availElems, installedElems;
 
-  if (source == sInstalled || compareVersions || printStatus)
+  if (source == sInstalled || compareVersions || printStatus) {
     installedElems = queryInstalled(*globals.state, globals.profile);
+  }
 
-  if (source == sAvailable || compareVersions)
+  if (source == sAvailable || compareVersions) {
     loadDerivations(*globals.state, globals.instSource.nixExprPath,
                     globals.instSource.systemFilter,
                     *globals.instSource.autoArgs, attrPath, availElems);
+  }
 
   DrvInfos elems_ = filterBySelector(
       *globals.state, source == sInstalled ? installedElems : availElems,
@@ -948,13 +987,15 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
   PathSet validPaths, substitutablePaths;
   if (printStatus || globals.prebuiltOnly) {
     PathSet paths;
-    for (auto& i : elems) try {
+    for (auto& i : elems) {
+      try {
         paths.insert(i.queryOutPath());
       } catch (AssertionError& e) {
         DLOG(WARNING) << "skipping derivation named '" << i.queryName()
                       << "' which gives an assertion failure";
         i.setFailed();
       }
+    }
     validPaths = globals.state->store->queryValidPaths(paths);
     substitutablePaths = globals.state->store->querySubstitutablePaths(paths);
   }
@@ -984,8 +1025,10 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
 
       if (globals.prebuiltOnly &&
           validPaths.find(i.queryOutPath()) == validPaths.end() &&
-          substitutablePaths.find(i.queryOutPath()) == substitutablePaths.end())
+          substitutablePaths.find(i.queryOutPath()) ==
+              substitutablePaths.end()) {
         continue;
+      }
 
       /* For table output. */
       Strings columns;
@@ -1003,15 +1046,17 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
           attrs["installed"] = isInstalled ? "1" : "0";
           attrs["valid"] = isValid ? "1" : "0";
           attrs["substitutable"] = hasSubs ? "1" : "0";
-        } else
+        } else {
           columns.push_back((string)(isInstalled ? "I" : "-") +
                             (isValid ? "P" : "-") + (hasSubs ? "S" : "-"));
+        }
       }
 
-      if (xmlOutput)
+      if (xmlOutput) {
         attrs["attrPath"] = i.attrPath;
-      else if (printAttrPath)
+      } else if (printAttrPath) {
         columns.push_back(i.attrPath);
+      }
 
       if (xmlOutput) {
         auto drvName = DrvName(i.queryName());
@@ -1055,8 +1100,9 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
           }
         } else {
           string column = (string) "" + ch + " " + version;
-          if (diff == cvGreater && tty)
+          if (diff == cvGreater && tty) {
             column = ANSI_RED + column + ANSI_NORMAL;
+          }
           columns.push_back(column);
         }
       }
@@ -1065,8 +1111,9 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
         if (i.querySystem() != "") {
           attrs["system"] = i.querySystem();
         }
-      } else if (printSystem)
+      } else if (printSystem) {
         columns.push_back(i.querySystem());
+      }
 
       if (printDrvPath) {
         string drvPath = i.queryDrvPath();
@@ -1074,8 +1121,9 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
           if (drvPath != "") {
             attrs["drvPath"] = drvPath;
           }
-        } else
+        } else {
           columns.push_back(drvPath == "" ? "-" : drvPath);
+        }
       }
 
       if (printOutPath && !xmlOutput) {
@@ -1100,8 +1148,9 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
           if (descr != "") {
             attrs["description"] = descr;
           }
-        } else
+        } else {
           columns.push_back(descr);
+        }
       }
 
       if (xmlOutput) {
@@ -1171,10 +1220,12 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
               }
             }
           }
-        } else
+        } else {
           xml.writeEmptyElement("item", attrs);
-      } else
+        }
+      } else {
         table.push_back(columns);
+      }
 
       cout.flush();
 
@@ -1194,10 +1245,12 @@ static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
 }
 
 static void opSwitchProfile(Globals& globals, Strings opFlags, Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-  if (opArgs.size() != 1)
+  }
+  if (opArgs.size() != 1) {
     throw UsageError(format("exactly one argument expected"));
+  }
 
   Path profile = absPath(opArgs.front());
   Path profileLink = getHome() + "/.nix-profile";
@@ -1215,17 +1268,20 @@ static void switchGeneration(Globals& globals, int dstGen) {
   Generations gens = findGenerations(globals.profile, curGen);
 
   Generation dst;
-  for (auto& i : gens)
+  for (auto& i : gens) {
     if ((dstGen == prevGen && i.number < curGen) ||
-        (dstGen >= 0 && i.number == dstGen))
+        (dstGen >= 0 && i.number == dstGen)) {
       dst = i;
+    }
+  }
 
   if (!dst) {
-    if (dstGen == prevGen)
+    if (dstGen == prevGen) {
       throw Error(format("no generation older than the current (%1%) exists") %
                   curGen);
-    else
+    } else {
       throw Error(format("generation %1% does not exist") % dstGen);
+    }
   }
 
   LOG(INFO) << "switching from generation " << curGen << " to " << dst.number;
@@ -1239,21 +1295,25 @@ static void switchGeneration(Globals& globals, int dstGen) {
 
 static void opSwitchGeneration(Globals& globals, Strings opFlags,
                                Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-  if (opArgs.size() != 1)
+  }
+  if (opArgs.size() != 1) {
     throw UsageError(format("exactly one argument expected"));
+  }
 
   int dstGen;
-  if (!string2Int(opArgs.front(), dstGen))
+  if (!string2Int(opArgs.front(), dstGen)) {
     throw UsageError(format("expected a generation number"));
+  }
 
   switchGeneration(globals, dstGen);
 }
 
 static void opRollback(Globals& globals, Strings opFlags, Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  }
   if (opArgs.size() != 0) {
     throw UsageError(format("no arguments expected"));
   }
@@ -1263,8 +1323,9 @@ static void opRollback(Globals& globals, Strings opFlags, Strings opArgs) {
 
 static void opListGenerations(Globals& globals, Strings opFlags,
                               Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  }
   if (opArgs.size() != 0) {
     throw UsageError(format("no arguments expected"));
   }
@@ -1291,29 +1352,33 @@ static void opListGenerations(Globals& globals, Strings opFlags,
 
 static void opDeleteGenerations(Globals& globals, Strings opFlags,
                                 Strings opArgs) {
-  if (opFlags.size() > 0)
+  if (opFlags.size() > 0) {
     throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  }
 
   if (opArgs.size() == 1 && opArgs.front() == "old") {
     deleteOldGenerations(globals.profile, globals.dryRun);
   } else if (opArgs.size() == 1 && opArgs.front().find('d') != string::npos) {
     deleteGenerationsOlderThan(globals.profile, opArgs.front(), globals.dryRun);
   } else if (opArgs.size() == 1 && opArgs.front().find('+') != string::npos) {
-    if (opArgs.front().size() < 2)
+    if (opArgs.front().size() < 2) {
       throw Error(format("invalid number of generations ‘%1%’") %
                   opArgs.front());
+    }
     string str_max = string(opArgs.front(), 1, opArgs.front().size());
     int max;
-    if (!string2Int(str_max, max) || max == 0)
+    if (!string2Int(str_max, max) || max == 0) {
       throw Error(format("invalid number of generations to keep ‘%1%’") %
                   opArgs.front());
+    }
     deleteGenerationsGreaterThan(globals.profile, max, globals.dryRun);
   } else {
     std::set<unsigned int> gens;
     for (auto& i : opArgs) {
       unsigned int n;
-      if (!string2Int(i, n))
+      if (!string2Int(i, n)) {
         throw UsageError(format("invalid generation number '%1%'") % i);
+      }
       gens.insert(n);
     }
     deleteGenerations(globals.profile, gens, globals.dryRun);
@@ -1343,10 +1408,11 @@ static int _main(int argc, char** argv) {
         replaceSymlink(fmt("%s/profiles/per-user/%s/channels",
                            settings.nixStateDir, getUserName()),
                        globals.instSource.nixExprPath + "/channels");
-        if (getuid() != 0)
+        if (getuid() != 0) {
           replaceSymlink(
               fmt("%s/profiles/per-user/root/channels", settings.nixStateDir),
               globals.instSource.nixExprPath + "/channels_root");
+        }
       } catch (Error&) {
       }
     }
@@ -1364,59 +1430,62 @@ static int _main(int argc, char** argv) {
                                            const Strings::iterator& end) {
       Operation oldOp = op;
 
-      if (*arg == "--help")
+      if (*arg == "--help") {
         showManPage("nix-env");
-      else if (*arg == "--version")
+      } else if (*arg == "--version") {
         op = opVersion;
-      else if (*arg == "--install" || *arg == "-i")
+      } else if (*arg == "--install" || *arg == "-i") {
         op = opInstall;
-      else if (*arg ==
-               "--force-name")  // undocumented flag for nix-install-package
+      } else if (*arg ==
+                 "--force-name") {  // undocumented flag for nix-install-package
         globals.forceName = getArg(*arg, arg, end);
-      else if (*arg == "--uninstall" || *arg == "-e")
+      } else if (*arg == "--uninstall" || *arg == "-e") {
         op = opUninstall;
-      else if (*arg == "--upgrade" || *arg == "-u")
+      } else if (*arg == "--upgrade" || *arg == "-u") {
         op = opUpgrade;
-      else if (*arg == "--set-flag")
+      } else if (*arg == "--set-flag") {
         op = opSetFlag;
-      else if (*arg == "--set")
+      } else if (*arg == "--set") {
         op = opSet;
-      else if (*arg == "--query" || *arg == "-q")
+      } else if (*arg == "--query" || *arg == "-q") {
         op = opQuery;
-      else if (*arg == "--profile" || *arg == "-p")
+      } else if (*arg == "--profile" || *arg == "-p") {
         globals.profile = absPath(getArg(*arg, arg, end));
-      else if (*arg == "--file" || *arg == "-f")
+      } else if (*arg == "--file" || *arg == "-f") {
         file = getArg(*arg, arg, end);
-      else if (*arg == "--switch-profile" || *arg == "-S")
+      } else if (*arg == "--switch-profile" || *arg == "-S") {
         op = opSwitchProfile;
-      else if (*arg == "--switch-generation" || *arg == "-G")
+      } else if (*arg == "--switch-generation" || *arg == "-G") {
         op = opSwitchGeneration;
-      else if (*arg == "--rollback")
+      } else if (*arg == "--rollback") {
         op = opRollback;
-      else if (*arg == "--list-generations")
+      } else if (*arg == "--list-generations") {
         op = opListGenerations;
-      else if (*arg == "--delete-generations")
+      } else if (*arg == "--delete-generations") {
         op = opDeleteGenerations;
-      else if (*arg == "--dry-run") {
+      } else if (*arg == "--dry-run") {
         LOG(INFO) << "(dry run; not doing anything)";
         globals.dryRun = true;
-      } else if (*arg == "--system-filter")
+      } else if (*arg == "--system-filter") {
         globals.instSource.systemFilter = getArg(*arg, arg, end);
-      else if (*arg == "--prebuilt-only" || *arg == "-b")
+      } else if (*arg == "--prebuilt-only" || *arg == "-b") {
         globals.prebuiltOnly = true;
-      else if (*arg == "--repair")
+      } else if (*arg == "--repair") {
         repair = Repair;
-      else if (*arg != "" && arg->at(0) == '-') {
+      } else if (*arg != "" && arg->at(0) == '-') {
         opFlags.push_back(*arg);
         /* FIXME: hacky */
         if (*arg == "--from-profile" ||
-            (op == opQuery && (*arg == "--attr" || *arg == "-A")))
+            (op == opQuery && (*arg == "--attr" || *arg == "-A"))) {
           opFlags.push_back(getArg(*arg, arg, end));
-      } else
+        }
+      } else {
         opArgs.push_back(*arg);
+      }
 
-      if (oldOp && oldOp != op)
+      if (oldOp && oldOp != op) {
         throw UsageError("only one operation may be specified");
+      }
 
       return true;
     });
@@ -1435,8 +1504,9 @@ static int _main(int argc, char** argv) {
         std::shared_ptr<EvalState>(new EvalState(myArgs.searchPath, store));
     globals.state->repair = repair;
 
-    if (file != "")
+    if (file != "") {
       globals.instSource.nixExprPath = lookupFileArg(*globals.state, file);
+    }
 
     globals.instSource.autoArgs = myArgs.getAutoArgs(*globals.state);
 
diff --git a/third_party/nix/src/nix-env/user-env.cc b/third_party/nix/src/nix-env/user-env.cc
index 0719c8a51d..d013f34b08 100644
--- a/third_party/nix/src/nix-env/user-env.cc
+++ b/third_party/nix/src/nix-env/user-env.cc
@@ -30,10 +30,11 @@ bool createUserEnv(EvalState& state, DrvInfos& elems, const Path& profile,
   /* Build the components in the user environment, if they don't
      exist already. */
   PathSet drvsToBuild;
-  for (auto& i : elems)
+  for (auto& i : elems) {
     if (i.queryDrvPath() != "") {
       drvsToBuild.insert(i.queryDrvPath());
     }
+  }
 
   DLOG(INFO) << "building user environment dependencies";
   state.store->buildPaths(drvsToBuild, state.repair ? bmRepair : bmNormal);
@@ -60,8 +61,9 @@ bool createUserEnv(EvalState& state, DrvInfos& elems, const Path& profile,
       mkString(*state.allocAttr(v, state.sSystem), system);
     }
     mkString(*state.allocAttr(v, state.sOutPath), i.queryOutPath());
-    if (drvPath != "")
+    if (drvPath != "") {
       mkString(*state.allocAttr(v, state.sDrvPath), i.queryDrvPath());
+    }
 
     // Copy each output meant for installation.
     DrvInfo::Outputs outputs = i.queryOutputs(true);
diff --git a/third_party/nix/src/nix-instantiate/nix-instantiate.cc b/third_party/nix/src/nix-instantiate/nix-instantiate.cc
index 20dcd7f42d..05f481906b 100644
--- a/third_party/nix/src/nix-instantiate/nix-instantiate.cc
+++ b/third_party/nix/src/nix-instantiate/nix-instantiate.cc
@@ -40,15 +40,16 @@ void processExpr(EvalState& state, const Strings& attrPaths, bool parseOnly,
     PathSet context;
     if (evalOnly) {
       Value vRes;
-      if (autoArgs.empty())
+      if (autoArgs.empty()) {
         vRes = v;
-      else
+      } else {
         state.autoCallFunction(autoArgs, v, vRes);
-      if (output == okXML)
+      }
+      if (output == okXML) {
         printValueAsXML(state, strict, location, vRes, std::cout, context);
-      else if (output == okJSON)
+      } else if (output == okJSON) {
         printValueAsJSON(state, strict, vRes, std::cout, context);
-      else {
+      } else {
         if (strict) {
           state.forceValueDeep(vRes);
         }
@@ -62,21 +63,23 @@ void processExpr(EvalState& state, const Strings& attrPaths, bool parseOnly,
 
         /* What output do we want? */
         string outputName = i.queryOutputName();
-        if (outputName == "")
+        if (outputName == "") {
           throw Error(
               format("derivation '%1%' lacks an 'outputName' attribute ") %
               drvPath);
+        }
 
-        if (gcRoot == "")
+        if (gcRoot == "") {
           printGCWarning();
-        else {
+        } else {
           Path rootName = indirectRoot ? absPath(gcRoot) : gcRoot;
           if (++rootNr > 1) {
             rootName += "-" + std::to_string(rootNr);
           }
           auto store2 = state.store.dynamic_pointer_cast<LocalFSStore>();
-          if (store2)
+          if (store2) {
             drvPath = store2->addPermRoot(drvPath, rootName, indirectRoot);
+          }
         }
         std::cout << format("%1%%2%\n") % drvPath %
                          (outputName != "out" ? "!" + outputName : "");
@@ -106,44 +109,45 @@ static int _main(int argc, char** argv) {
 
     MyArgs myArgs(baseNameOf(argv[0]),
                   [&](Strings::iterator& arg, const Strings::iterator& end) {
-                    if (*arg == "--help")
+                    if (*arg == "--help") {
                       showManPage("nix-instantiate");
-                    else if (*arg == "--version")
+                    } else if (*arg == "--version") {
                       printVersion("nix-instantiate");
-                    else if (*arg == "-")
+                    } else if (*arg == "-") {
                       readStdin = true;
-                    else if (*arg == "--expr" || *arg == "-E")
+                    } else if (*arg == "--expr" || *arg == "-E") {
                       fromArgs = true;
-                    else if (*arg == "--eval" || *arg == "--eval-only")
+                    } else if (*arg == "--eval" || *arg == "--eval-only") {
                       evalOnly = true;
-                    else if (*arg == "--read-write-mode")
+                    } else if (*arg == "--read-write-mode") {
                       wantsReadWrite = true;
-                    else if (*arg == "--parse" || *arg == "--parse-only")
+                    } else if (*arg == "--parse" || *arg == "--parse-only") {
                       parseOnly = evalOnly = true;
-                    else if (*arg == "--find-file")
+                    } else if (*arg == "--find-file") {
                       findFile = true;
-                    else if (*arg == "--attr" || *arg == "-A")
+                    } else if (*arg == "--attr" || *arg == "-A") {
                       attrPaths.push_back(getArg(*arg, arg, end));
-                    else if (*arg == "--add-root")
+                    } else if (*arg == "--add-root") {
                       gcRoot = getArg(*arg, arg, end);
-                    else if (*arg == "--indirect")
+                    } else if (*arg == "--indirect") {
                       indirectRoot = true;
-                    else if (*arg == "--xml")
+                    } else if (*arg == "--xml") {
                       outputKind = okXML;
-                    else if (*arg == "--json")
+                    } else if (*arg == "--json") {
                       outputKind = okJSON;
-                    else if (*arg == "--no-location")
+                    } else if (*arg == "--no-location") {
                       xmlOutputSourceLocation = false;
-                    else if (*arg == "--strict")
+                    } else if (*arg == "--strict") {
                       strict = true;
-                    else if (*arg == "--repair")
+                    } else if (*arg == "--repair") {
                       repair = Repair;
-                    else if (*arg == "--dry-run")
+                    } else if (*arg == "--dry-run") {
                       settings.readOnlyMode = true;
-                    else if (*arg != "" && arg->at(0) == '-')
+                    } else if (*arg != "" && arg->at(0) == '-') {
                       return false;
-                    else
+                    } else {
                       files.push_back(*arg);
+                    }
                     return true;
                   });
 
diff --git a/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc b/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc
index 96d8540958..8c92af19d5 100644
--- a/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc
+++ b/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -40,12 +40,14 @@ string resolveMirrorUri(EvalState& state, string uri) {
   state.forceAttrs(vMirrors);
 
   auto mirrorList = vMirrors.attrs->find(state.symbols.create(mirrorName));
-  if (mirrorList == vMirrors.attrs->end())
+  if (mirrorList == vMirrors.attrs->end()) {
     throw Error(format("unknown mirror name '%1%'") % mirrorName);
+  }
   state.forceList(*mirrorList->value);
 
-  if (mirrorList->value->listSize() < 1)
+  if (mirrorList->value->listSize() < 1) {
     throw Error(format("mirror URI '%1%' did not expand to anything") % uri);
+  }
 
   string mirror = state.forceString(*mirrorList->value->listElems()[0]);
   return mirror + (hasSuffix(mirror, "/") ? "" : "/") + string(s, p + 1);
@@ -67,28 +69,30 @@ static int _main(int argc, char** argv) {
 
     MyArgs myArgs(baseNameOf(argv[0]),
                   [&](Strings::iterator& arg, const Strings::iterator& end) {
-                    if (*arg == "--help")
+                    if (*arg == "--help") {
                       showManPage("nix-prefetch-url");
-                    else if (*arg == "--version")
+                    } else if (*arg == "--version") {
                       printVersion("nix-prefetch-url");
-                    else if (*arg == "--type") {
+                    } else if (*arg == "--type") {
                       string s = getArg(*arg, arg, end);
                       ht = parseHashType(s);
-                      if (ht == htUnknown)
+                      if (ht == htUnknown) {
                         throw UsageError(format("unknown hash type '%1%'") % s);
-                    } else if (*arg == "--print-path")
+                      }
+                    } else if (*arg == "--print-path") {
                       printPath = true;
-                    else if (*arg == "--attr" || *arg == "-A") {
+                    } else if (*arg == "--attr" || *arg == "-A") {
                       fromExpr = true;
                       attrPath = getArg(*arg, arg, end);
-                    } else if (*arg == "--unpack")
+                    } else if (*arg == "--unpack") {
                       unpack = true;
-                    else if (*arg == "--name")
+                    } else if (*arg == "--name") {
                       name = getArg(*arg, arg, end);
-                    else if (*arg != "" && arg->at(0) == '-')
+                    } else if (*arg != "" && arg->at(0) == '-') {
                       return false;
-                    else
+                    } else {
                       args.push_back(*arg);
+                    }
                     return true;
                   });
 
@@ -123,8 +127,9 @@ static int _main(int argc, char** argv) {
 
       /* Extract the URI. */
       auto attr = v.attrs->find(state->symbols.create("urls"));
-      if (attr == v.attrs->end())
+      if (attr == v.attrs->end()) {
         throw Error("attribute set does not contain a 'urls' attribute");
+      }
       state->forceList(*attr->value);
       if (attr->value->listSize() < 1) {
         throw Error("'urls' list is empty");
@@ -133,10 +138,11 @@ static int _main(int argc, char** argv) {
 
       /* Extract the hash mode. */
       attr = v.attrs->find(state->symbols.create("outputHashMode"));
-      if (attr == v.attrs->end())
+      if (attr == v.attrs->end()) {
         LOG(WARNING) << "this does not look like a fetchurl call";
-      else
+      } else {
         unpack = state->forceString(*attr->value) == "recursive";
+      }
 
       /* Extract the name. */
       if (name.empty()) {
@@ -151,8 +157,9 @@ static int _main(int argc, char** argv) {
     if (name.empty()) {
       name = baseNameOf(uri);
     }
-    if (name.empty())
+    if (name.empty()) {
       throw Error(format("cannot figure out file name for '%1%'") % uri);
+    }
 
     /* If an expected hash is given, the file may already exist in
        the store. */
@@ -161,10 +168,11 @@ static int _main(int argc, char** argv) {
     if (args.size() == 2) {
       expectedHash = Hash(args[1], ht);
       storePath = store->makeFixedOutputPath(unpack, expectedHash, name);
-      if (store->isValidPath(storePath))
+      if (store->isValidPath(storePath)) {
         hash = expectedHash;
-      else
+      } else {
         storePath.clear();
+      }
     }
 
     if (storePath.empty()) {
@@ -193,27 +201,30 @@ static int _main(int argc, char** argv) {
         LOG(INFO) << "unpacking...";
         Path unpacked = (Path)tmpDir + "/unpacked";
         createDirs(unpacked);
-        if (hasSuffix(baseNameOf(uri), ".zip"))
+        if (hasSuffix(baseNameOf(uri), ".zip")) {
           runProgram("unzip", true, {"-qq", tmpFile, "-d", unpacked});
-        else
+        } else {
           // FIXME: this requires GNU tar for decompression.
           runProgram("tar", true, {"xf", tmpFile, "-C", unpacked});
+        }
 
         /* If the archive unpacks to a single file/directory, then use
            that as the top-level. */
         auto entries = readDirectory(unpacked);
-        if (entries.size() == 1)
+        if (entries.size() == 1) {
           tmpFile = unpacked + "/" + entries[0].name;
-        else
+        } else {
           tmpFile = unpacked;
+        }
       }
 
       /* FIXME: inefficient; addToStore() will also hash
          this. */
       hash = unpack ? hashPath(ht, tmpFile).first : hashFile(ht, tmpFile);
 
-      if (expectedHash != Hash(ht) && expectedHash != hash)
+      if (expectedHash != Hash(ht) && expectedHash != hash) {
         throw Error(format("hash mismatch for '%1%'") % uri);
+      }
 
       /* Copy the file to the Nix store. FIXME: if RemoteStore
          implemented addToStoreFromDump() and downloadFile()
diff --git a/third_party/nix/src/nix-store/nix-store.cc b/third_party/nix/src/nix-store/nix-store.cc
index 1df4b451e7..75cbae3f0f 100644
--- a/third_party/nix/src/nix-store/nix-store.cc
+++ b/third_party/nix/src/nix-store/nix-store.cc
@@ -38,8 +38,9 @@ static std::shared_ptr<Store> store;
 
 ref<LocalStore> ensureLocalStore() {
   auto store2 = std::dynamic_pointer_cast<LocalStore>(store);
-  if (!store2)
+  if (!store2) {
     throw Error("you don't have sufficient rights to use this command");
+  }
   return ref<LocalStore>(store2);
 }
 
@@ -48,8 +49,9 @@ static Path useDeriver(Path path) {
     return path;
   }
   Path drvPath = store->queryPathInfo(path)->deriver;
-  if (drvPath == "")
+  if (drvPath == "") {
     throw Error(format("deriver of path '%1%' is not known") % path);
+  }
   return drvPath;
 }
 
@@ -67,23 +69,25 @@ static PathSet realisePath(Path path, bool build = true) {
     Derivation drv = store->derivationFromPath(p.first);
     rootNr++;
 
-    if (p.second.empty())
+    if (p.second.empty()) {
       for (auto& i : drv.outputs) {
         p.second.insert(i.first);
       }
+    }
 
     PathSet outputs;
     for (auto& j : p.second) {
       DerivationOutputs::iterator i = drv.outputs.find(j);
-      if (i == drv.outputs.end())
+      if (i == drv.outputs.end()) {
         throw Error(
             format("derivation '%1%' does not have an output named '%2%'") %
             p.first % j);
+      }
       Path outPath = i->second.path;
       if (store2) {
-        if (gcRoot == "")
+        if (gcRoot == "") {
           printGCWarning();
-        else {
+        } else {
           Path rootName = gcRoot;
           if (rootNr > 1) {
             rootName += "-" + std::to_string(rootNr);
@@ -100,15 +104,16 @@ static PathSet realisePath(Path path, bool build = true) {
   }
 
   else {
-    if (build)
+    if (build) {
       store->ensurePath(path);
-    else if (!store->isValidPath(path))
+    } else if (!store->isValidPath(path)) {
       throw Error(format("path '%1%' does not exist and cannot be created") %
                   path);
+    }
     if (store2) {
-      if (gcRoot == "")
+      if (gcRoot == "") {
         printGCWarning();
-      else {
+      } else {
         Path rootName = gcRoot;
         rootNr++;
         if (rootNr > 1) {
@@ -127,17 +132,19 @@ static void opRealise(Strings opFlags, Strings opArgs) {
   BuildMode buildMode = bmNormal;
   bool ignoreUnknown = false;
 
-  for (auto& i : opFlags)
-    if (i == "--dry-run")
+  for (auto& i : opFlags) {
+    if (i == "--dry-run") {
       dryRun = true;
-    else if (i == "--repair")
+    } else if (i == "--repair") {
       buildMode = bmRepair;
-    else if (i == "--check")
+    } else if (i == "--check") {
       buildMode = bmCheck;
-    else if (i == "--ignore-unknown")
+    } else if (i == "--ignore-unknown") {
       ignoreUnknown = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   Paths paths;
   for (auto& i : opArgs) {
@@ -153,17 +160,19 @@ static void opRealise(Strings opFlags, Strings opArgs) {
 
   if (ignoreUnknown) {
     Paths paths2;
-    for (auto& i : paths)
+    for (auto& i : paths) {
       if (unknown.find(i) == unknown.end()) {
         paths2.push_back(i);
       }
+    }
     paths = paths2;
     unknown = PathSet();
   }
 
-  if (settings.printMissing)
+  if (settings.printMissing) {
     printMissing(ref<Store>(store), willBuild, willSubstitute, unknown,
                  downloadSize, narSize);
+  }
 
   if (dryRun) {
     return;
@@ -172,14 +181,16 @@ static void opRealise(Strings opFlags, Strings opArgs) {
   /* Build all paths at the same time to exploit parallelism. */
   store->buildPaths(PathSet(paths.begin(), paths.end()), buildMode);
 
-  if (!ignoreUnknown)
+  if (!ignoreUnknown) {
     for (auto& i : paths) {
       PathSet paths = realisePath(i, false);
-      if (!noOutput)
+      if (!noOutput) {
         for (auto& j : paths) {
           cout << format("%1%\n") % j;
         }
+      }
     }
+  }
 }
 
 /* Add files to the Nix store and print the resulting paths. */
@@ -188,8 +199,9 @@ static void opAdd(Strings opFlags, Strings opArgs) {
     throw UsageError("unknown flag");
   }
 
-  for (auto& i : opArgs)
+  for (auto& i : opArgs) {
     cout << format("%1%\n") % store->addToStore(baseNameOf(i), i);
+  }
 }
 
 /* Preload the output of a fixed-output derivation into the Nix
@@ -197,11 +209,13 @@ static void opAdd(Strings opFlags, Strings opArgs) {
 static void opAddFixed(Strings opFlags, Strings opArgs) {
   bool recursive = false;
 
-  for (auto& i : opFlags)
-    if (i == "--recursive")
+  for (auto& i : opFlags) {
+    if (i == "--recursive") {
       recursive = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   if (opArgs.empty()) {
     throw UsageError("first argument must be hash algorithm");
@@ -210,23 +224,27 @@ static void opAddFixed(Strings opFlags, Strings opArgs) {
   HashType hashAlgo = parseHashType(opArgs.front());
   opArgs.pop_front();
 
-  for (auto& i : opArgs)
+  for (auto& i : opArgs) {
     cout << format("%1%\n") %
                 store->addToStore(baseNameOf(i), i, recursive, hashAlgo);
+  }
 }
 
 /* Hack to support caching in `nix-prefetch-url'. */
 static void opPrintFixedPath(Strings opFlags, Strings opArgs) {
   bool recursive = false;
 
-  for (auto i : opFlags)
-    if (i == "--recursive")
+  for (auto i : opFlags) {
+    if (i == "--recursive") {
       recursive = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
-  if (opArgs.size() != 3)
+  if (opArgs.size() != 3) {
     throw UsageError(format("'--print-fixed-path' requires three arguments"));
+  }
 
   Strings::iterator i = opArgs.begin();
   HashType hashAlgo = parseHashType(*i++);
@@ -249,8 +267,9 @@ static PathSet maybeUseOutputs(const Path& storePath, bool useOutput,
       outputs.insert(i.second.path);
     }
     return outputs;
-  } else
+  } else {
     return {storePath};
+  }
 }
 
 /* Some code to print a tree representation of a derivation dependency
@@ -316,50 +335,52 @@ static void opQuery(Strings opFlags, Strings opArgs) {
 
   for (auto& i : opFlags) {
     QueryType prev = query;
-    if (i == "--outputs")
+    if (i == "--outputs") {
       query = qOutputs;
-    else if (i == "--requisites" || i == "-R")
+    } else if (i == "--requisites" || i == "-R") {
       query = qRequisites;
-    else if (i == "--references")
+    } else if (i == "--references") {
       query = qReferences;
-    else if (i == "--referrers" || i == "--referers")
+    } else if (i == "--referrers" || i == "--referers") {
       query = qReferrers;
-    else if (i == "--referrers-closure" || i == "--referers-closure")
+    } else if (i == "--referrers-closure" || i == "--referers-closure") {
       query = qReferrersClosure;
-    else if (i == "--deriver" || i == "-d")
+    } else if (i == "--deriver" || i == "-d") {
       query = qDeriver;
-    else if (i == "--binding" || i == "-b") {
+    } else if (i == "--binding" || i == "-b") {
       if (opArgs.size() == 0) {
         throw UsageError("expected binding name");
       }
       bindingName = opArgs.front();
       opArgs.pop_front();
       query = qBinding;
-    } else if (i == "--hash")
+    } else if (i == "--hash") {
       query = qHash;
-    else if (i == "--size")
+    } else if (i == "--size") {
       query = qSize;
-    else if (i == "--tree")
+    } else if (i == "--tree") {
       query = qTree;
-    else if (i == "--graph")
+    } else if (i == "--graph") {
       query = qGraph;
-    else if (i == "--graphml")
+    } else if (i == "--graphml") {
       query = qGraphML;
-    else if (i == "--resolve")
+    } else if (i == "--resolve") {
       query = qResolve;
-    else if (i == "--roots")
+    } else if (i == "--roots") {
       query = qRoots;
-    else if (i == "--use-output" || i == "-u")
+    } else if (i == "--use-output" || i == "-u") {
       useOutput = true;
-    else if (i == "--force-realise" || i == "--force-realize" || i == "-f")
+    } else if (i == "--force-realise" || i == "--force-realize" || i == "-f") {
       forceRealise = true;
-    else if (i == "--include-outputs")
+    } else if (i == "--include-outputs") {
       includeOutputs = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
-    if (prev != qDefault && prev != query)
+    }
+    if (prev != qDefault && prev != query) {
       throw UsageError(format("query type '%1%' conflicts with earlier flag") %
                        i);
+    }
   }
 
   if (query == qDefault) {
@@ -392,21 +413,24 @@ static void opQuery(Strings opFlags, Strings opArgs) {
         PathSet ps = maybeUseOutputs(store->followLinksToStorePath(i),
                                      useOutput, forceRealise);
         for (auto& j : ps) {
-          if (query == qRequisites)
+          if (query == qRequisites) {
             store->computeFSClosure(j, paths, false, includeOutputs);
-          else if (query == qReferences) {
+          } else if (query == qReferences) {
             for (auto& p : store->queryPathInfo(j)->references) {
               paths.insert(p);
             }
-          } else if (query == qReferrers)
+          } else if (query == qReferrers) {
             store->queryReferrers(j, paths);
-          else if (query == qReferrersClosure)
+          } else if (query == qReferrersClosure) {
             store->computeFSClosure(j, paths, true);
+          }
         }
       }
       Paths sorted = store->topoSortPaths(paths);
-      for (Paths::reverse_iterator i = sorted.rbegin(); i != sorted.rend(); ++i)
+      for (Paths::reverse_iterator i = sorted.rbegin(); i != sorted.rend();
+           ++i) {
         cout << format("%s\n") % *i;
+      }
       break;
     }
 
@@ -423,11 +447,12 @@ static void opQuery(Strings opFlags, Strings opArgs) {
         Path path = useDeriver(store->followLinksToStorePath(i));
         Derivation drv = store->derivationFromPath(path);
         StringPairs::iterator j = drv.env.find(bindingName);
-        if (j == drv.env.end())
+        if (j == drv.env.end()) {
           throw Error(
               format(
                   "derivation '%1%' has no environment binding named '%2%'") %
               path % bindingName);
+        }
         cout << format("%1%\n") % j->second;
       }
       break;
@@ -442,16 +467,18 @@ static void opQuery(Strings opFlags, Strings opArgs) {
           if (query == qHash) {
             assert(info->narHash.type == htSHA256);
             cout << fmt("%s\n", info->narHash.to_string(Base32));
-          } else if (query == qSize)
+          } else if (query == qSize) {
             cout << fmt("%d\n", info->narSize);
+          }
         }
       }
       break;
 
     case qTree: {
       PathSet done;
-      for (auto& i : opArgs)
+      for (auto& i : opArgs) {
         printTree(store->followLinksToStorePath(i), "", "", done);
+      }
       break;
     }
 
@@ -478,8 +505,9 @@ static void opQuery(Strings opFlags, Strings opArgs) {
     }
 
     case qResolve: {
-      for (auto& i : opArgs)
+      for (auto& i : opArgs) {
         cout << format("%1%\n") % store->followLinksToStorePath(i);
+      }
       break;
     }
 
@@ -493,10 +521,13 @@ static void opQuery(Strings opFlags, Strings opArgs) {
             settings.gcKeepDerivations);
       }
       Roots roots = store->findRoots(false);
-      for (auto& [target, links] : roots)
-        if (referrers.find(target) != referrers.end())
-          for (auto& link : links)
+      for (auto& [target, links] : roots) {
+        if (referrers.find(target) != referrers.end()) {
+          for (auto& link : links) {
             cout << format("%1% -> %2%\n") % link % target;
+          }
+        }
+      }
       break;
     }
 
@@ -509,16 +540,18 @@ static void opPrintEnv(Strings opFlags, Strings opArgs) {
   if (!opFlags.empty()) {
     throw UsageError("unknown flag");
   }
-  if (opArgs.size() != 1)
+  if (opArgs.size() != 1) {
     throw UsageError("'--print-env' requires one derivation store path");
+  }
 
   Path drvPath = opArgs.front();
   Derivation drv = store->derivationFromPath(drvPath);
 
   /* Print each environment variable in the derivation in a format
      that can be sourced by the shell. */
-  for (auto& i : drv.env)
+  for (auto& i : drv.env) {
     cout << format("export %1%; %1%=%2%\n") % i.first % shellEscape(i.second);
+  }
 
   /* Also output the arguments.  This doesn't preserve whitespace in
      arguments. */
@@ -544,8 +577,9 @@ static void opReadLog(Strings opFlags, Strings opArgs) {
   for (auto& i : opArgs) {
     auto path = store->followLinksToStorePath(i);
     auto log = store->getBuildLog(path);
-    if (!log)
+    if (!log) {
       throw Error("build log of derivation '%s' is not available", path);
+    }
     std::cout << *log;
   }
 }
@@ -558,12 +592,14 @@ static void opDumpDB(Strings opFlags, Strings opArgs) {
     for (auto& i : opArgs) {
       i = store->followLinksToStorePath(i);
     }
-    for (auto& i : opArgs)
+    for (auto& i : opArgs) {
       cout << store->makeValidityRegistration({i}, true, true);
+    }
   } else {
     PathSet validPaths = store->queryAllValidPaths();
-    for (auto& i : validPaths)
+    for (auto& i : validPaths) {
       cout << store->makeValidityRegistration({i}, true, true);
+    }
   }
 }
 
@@ -607,13 +643,15 @@ static void opRegisterValidity(Strings opFlags, Strings opArgs) {
   bool reregister = false;  // !!! maybe this should be the default
   bool hashGiven = false;
 
-  for (auto& i : opFlags)
-    if (i == "--reregister")
+  for (auto& i : opFlags) {
+    if (i == "--reregister") {
       reregister = true;
-    else if (i == "--hash-given")
+    } else if (i == "--hash-given") {
       hashGiven = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   if (!opArgs.empty()) {
     throw UsageError("no arguments expected");
@@ -625,19 +663,22 @@ static void opRegisterValidity(Strings opFlags, Strings opArgs) {
 static void opCheckValidity(Strings opFlags, Strings opArgs) {
   bool printInvalid = false;
 
-  for (auto& i : opFlags)
-    if (i == "--print-invalid")
+  for (auto& i : opFlags) {
+    if (i == "--print-invalid") {
       printInvalid = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   for (auto& i : opArgs) {
     Path path = store->followLinksToStorePath(i);
     if (!store->isValidPath(path)) {
-      if (printInvalid)
+      if (printInvalid) {
         cout << format("%1%\n") % path;
-      else
+      } else {
         throw Error(format("path '%1%' is not valid") % path);
+      }
     }
   }
 }
@@ -650,20 +691,22 @@ static void opGC(Strings opFlags, Strings opArgs) {
   GCResults results;
 
   /* Do what? */
-  for (auto i = opFlags.begin(); i != opFlags.end(); ++i)
-    if (*i == "--print-roots")
+  for (auto i = opFlags.begin(); i != opFlags.end(); ++i) {
+    if (*i == "--print-roots") {
       printRoots = true;
-    else if (*i == "--print-live")
+    } else if (*i == "--print-live") {
       options.action = GCOptions::gcReturnLive;
-    else if (*i == "--print-dead")
+    } else if (*i == "--print-dead") {
       options.action = GCOptions::gcReturnDead;
-    else if (*i == "--delete")
+    } else if (*i == "--delete") {
       options.action = GCOptions::gcDeleteDead;
-    else if (*i == "--max-freed") {
+    } else if (*i == "--max-freed") {
       long long maxFreed = getIntArg<long long>(*i, i, opFlags.end(), true);
       options.maxFreed = maxFreed >= 0 ? maxFreed : 0;
-    } else
+    } else {
       throw UsageError(format("bad sub-operation '%1%' in GC") % *i);
+    }
+  }
 
   if (!opArgs.empty()) {
     throw UsageError("no arguments expected");
@@ -673,22 +716,25 @@ static void opGC(Strings opFlags, Strings opArgs) {
     Roots roots = store->findRoots(false);
     std::set<std::pair<Path, Path>> roots2;
     // Transpose and sort the roots.
-    for (auto& [target, links] : roots)
+    for (auto& [target, links] : roots) {
       for (auto& link : links) {
         roots2.emplace(link, target);
       }
-    for (auto& [link, target] : roots2)
+    }
+    for (auto& [link, target] : roots2) {
       std::cout << link << " -> " << target << "\n";
+    }
   }
 
   else {
     PrintFreed freed(options.action == GCOptions::gcDeleteDead, results);
     store->collectGarbage(options, results);
 
-    if (options.action != GCOptions::gcDeleteDead)
+    if (options.action != GCOptions::gcDeleteDead) {
       for (auto& i : results.paths) {
         cout << i << std::endl;
       }
+    }
   }
 }
 
@@ -699,14 +745,17 @@ static void opDelete(Strings opFlags, Strings opArgs) {
   GCOptions options;
   options.action = GCOptions::gcDeleteSpecific;
 
-  for (auto& i : opFlags)
-    if (i == "--ignore-liveness")
+  for (auto& i : opFlags) {
+    if (i == "--ignore-liveness") {
       options.ignoreLiveness = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
-  for (auto& i : opArgs)
+  for (auto& i : opArgs) {
     options.pathsToDelete.insert(store->followLinksToStorePath(i));
+  }
 
   GCResults results;
   PrintFreed freed(true, results);
@@ -795,13 +844,15 @@ static void opVerify(Strings opFlags, Strings opArgs) {
   bool checkContents = false;
   RepairFlag repair = NoRepair;
 
-  for (auto& i : opFlags)
-    if (i == "--check-contents")
+  for (auto& i : opFlags) {
+    if (i == "--check-contents") {
       checkContents = true;
-    else if (i == "--repair")
+    } else if (i == "--repair") {
       repair = Repair;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   if (store->verifyStore(checkContents, repair)) {
     LOG(WARNING) << "not all errors were fixed";
@@ -851,8 +902,9 @@ static void opRepairPath(Strings opFlags, Strings opArgs) {
 /* Optimise the disk space usage of the Nix store by hard-linking
    files with the same contents. */
 static void opOptimise(Strings opFlags, Strings opArgs) {
-  if (!opArgs.empty() || !opFlags.empty())
+  if (!opArgs.empty() || !opFlags.empty()) {
     throw UsageError("no arguments expected");
+  }
 
   store->optimiseStore();
 }
@@ -860,11 +912,13 @@ static void opOptimise(Strings opFlags, Strings opArgs) {
 /* Serve the nix store in a way usable by a restricted ssh user. */
 static void opServe(Strings opFlags, Strings opArgs) {
   bool writeAllowed = false;
-  for (auto& i : opFlags)
-    if (i == "--write")
+  for (auto& i : opFlags) {
+    if (i == "--write") {
       writeAllowed = true;
-    else
+    } else {
       throw UsageError(format("unknown flag '%1%'") % i);
+    }
+  }
 
   if (!opArgs.empty()) {
     throw UsageError("no arguments expected");
@@ -889,8 +943,9 @@ static void opServe(Strings opFlags, Strings opArgs) {
     settings.useSubstitutes = false;
     settings.maxSilentTime = readInt(in);
     settings.buildTimeout = readInt(in);
-    if (GET_PROTOCOL_MINOR(clientVersion) >= 2)
+    if (GET_PROTOCOL_MINOR(clientVersion) >= 2) {
       settings.maxLogSize = readNum<unsigned long>(in);
+    }
     if (GET_PROTOCOL_MINOR(clientVersion) >= 3) {
       settings.buildRepeat = readInt(in);
       settings.enforceDeterminism = readInt(in);
@@ -912,10 +967,11 @@ static void opServe(Strings opFlags, Strings opArgs) {
         bool lock = readInt(in);
         bool substitute = readInt(in);
         PathSet paths = readStorePaths<PathSet>(*store, in);
-        if (lock && writeAllowed)
+        if (lock && writeAllowed) {
           for (auto& path : paths) {
             store->addTempRoot(path);
           }
+        }
 
         /* If requested, substitute missing paths. This
            implements nix-copy-closure's --use-substitutes
@@ -923,21 +979,24 @@ static void opServe(Strings opFlags, Strings opArgs) {
         if (substitute && writeAllowed) {
           /* Filter out .drv files (we don't want to build anything). */
           PathSet paths2;
-          for (auto& path : paths)
+          for (auto& path : paths) {
             if (!isDerivation(path)) {
               paths2.insert(path);
             }
+          }
           unsigned long long downloadSize, narSize;
           PathSet willBuild, willSubstitute, unknown;
           store->queryMissing(PathSet(paths2.begin(), paths2.end()), willBuild,
                               willSubstitute, unknown, downloadSize, narSize);
           /* FIXME: should use ensurePath(), but it only
              does one path at a time. */
-          if (!willSubstitute.empty()) try {
+          if (!willSubstitute.empty()) {
+            try {
               store->buildPaths(willSubstitute);
             } catch (Error& e) {
               LOG(WARNING) << e.msg();
             }
+          }
         }
 
         out << store->queryValidPaths(paths);
@@ -954,9 +1013,10 @@ static void opServe(Strings opFlags, Strings opArgs) {
             // !!! Maybe we want compression?
             out << info->narSize  // downloadSize
                 << info->narSize;
-            if (GET_PROTOCOL_MINOR(clientVersion) >= 4)
+            if (GET_PROTOCOL_MINOR(clientVersion) >= 4) {
               out << (info->narHash ? info->narHash.to_string() : "")
                   << info->ca << info->sigs;
+            }
           } catch (InvalidPath&) {
           }
         }
@@ -1020,9 +1080,10 @@ static void opServe(Strings opFlags, Strings opArgs) {
 
         out << status.status << status.errorMsg;
 
-        if (GET_PROTOCOL_MINOR(clientVersion) >= 3)
+        if (GET_PROTOCOL_MINOR(clientVersion) >= 3) {
           out << status.timesBuilt << status.isNonDeterministic
               << status.startTime << status.stopTime;
+        }
 
         break;
       }
@@ -1127,81 +1188,85 @@ static int _main(int argc, char** argv) {
     Strings opFlags, opArgs;
     Operation op = 0;
 
-    parseCmdLine(
-        argc, argv, [&](Strings::iterator& arg, const Strings::iterator& end) {
-          Operation oldOp = op;
-
-          if (*arg == "--help")
-            showManPage("nix-store");
-          else if (*arg == "--version")
-            op = opVersion;
-          else if (*arg == "--realise" || *arg == "--realize" || *arg == "-r")
-            op = opRealise;
-          else if (*arg == "--add" || *arg == "-A")
-            op = opAdd;
-          else if (*arg == "--add-fixed")
-            op = opAddFixed;
-          else if (*arg == "--print-fixed-path")
-            op = opPrintFixedPath;
-          else if (*arg == "--delete")
-            op = opDelete;
-          else if (*arg == "--query" || *arg == "-q")
-            op = opQuery;
-          else if (*arg == "--print-env")
-            op = opPrintEnv;
-          else if (*arg == "--read-log" || *arg == "-l")
-            op = opReadLog;
-          else if (*arg == "--dump-db")
-            op = opDumpDB;
-          else if (*arg == "--load-db")
-            op = opLoadDB;
-          else if (*arg == "--register-validity")
-            op = opRegisterValidity;
-          else if (*arg == "--check-validity")
-            op = opCheckValidity;
-          else if (*arg == "--gc")
-            op = opGC;
-          else if (*arg == "--dump")
-            op = opDump;
-          else if (*arg == "--restore")
-            op = opRestore;
-          else if (*arg == "--export")
-            op = opExport;
-          else if (*arg == "--import")
-            op = opImport;
-          else if (*arg == "--init")
-            op = opInit;
-          else if (*arg == "--verify")
-            op = opVerify;
-          else if (*arg == "--verify-path")
-            op = opVerifyPath;
-          else if (*arg == "--repair-path")
-            op = opRepairPath;
-          else if (*arg == "--optimise" || *arg == "--optimize")
-            op = opOptimise;
-          else if (*arg == "--serve")
-            op = opServe;
-          else if (*arg == "--generate-binary-cache-key")
-            op = opGenerateBinaryCacheKey;
-          else if (*arg == "--add-root")
-            gcRoot = absPath(getArg(*arg, arg, end));
-          else if (*arg == "--indirect")
-            indirectRoot = true;
-          else if (*arg == "--no-output")
-            noOutput = true;
-          else if (*arg != "" && arg->at(0) == '-') {
-            opFlags.push_back(*arg);
-            if (*arg == "--max-freed" || *arg == "--max-links" ||
-                *arg == "--max-atime") /* !!! hack */
-              opFlags.push_back(getArg(*arg, arg, end));
-          } else
-            opArgs.push_back(*arg);
-
-          if (oldOp && oldOp != op)
-            throw UsageError("only one operation may be specified");
-
-          return true;
-        });
+    parseCmdLine(argc, argv,
+                 [&](Strings::iterator& arg, const Strings::iterator& end) {
+                   Operation oldOp = op;
+
+                   if (*arg == "--help") {
+                     showManPage("nix-store");
+                   } else if (*arg == "--version") {
+                     op = opVersion;
+                   } else if (*arg == "--realise" || *arg == "--realize" ||
+                              *arg == "-r") {
+                     op = opRealise;
+                   } else if (*arg == "--add" || *arg == "-A") {
+                     op = opAdd;
+                   } else if (*arg == "--add-fixed") {
+                     op = opAddFixed;
+                   } else if (*arg == "--print-fixed-path") {
+                     op = opPrintFixedPath;
+                   } else if (*arg == "--delete") {
+                     op = opDelete;
+                   } else if (*arg == "--query" || *arg == "-q") {
+                     op = opQuery;
+                   } else if (*arg == "--print-env") {
+                     op = opPrintEnv;
+                   } else if (*arg == "--read-log" || *arg == "-l") {
+                     op = opReadLog;
+                   } else if (*arg == "--dump-db") {
+                     op = opDumpDB;
+                   } else if (*arg == "--load-db") {
+                     op = opLoadDB;
+                   } else if (*arg == "--register-validity") {
+                     op = opRegisterValidity;
+                   } else if (*arg == "--check-validity") {
+                     op = opCheckValidity;
+                   } else if (*arg == "--gc") {
+                     op = opGC;
+                   } else if (*arg == "--dump") {
+                     op = opDump;
+                   } else if (*arg == "--restore") {
+                     op = opRestore;
+                   } else if (*arg == "--export") {
+                     op = opExport;
+                   } else if (*arg == "--import") {
+                     op = opImport;
+                   } else if (*arg == "--init") {
+                     op = opInit;
+                   } else if (*arg == "--verify") {
+                     op = opVerify;
+                   } else if (*arg == "--verify-path") {
+                     op = opVerifyPath;
+                   } else if (*arg == "--repair-path") {
+                     op = opRepairPath;
+                   } else if (*arg == "--optimise" || *arg == "--optimize") {
+                     op = opOptimise;
+                   } else if (*arg == "--serve") {
+                     op = opServe;
+                   } else if (*arg == "--generate-binary-cache-key") {
+                     op = opGenerateBinaryCacheKey;
+                   } else if (*arg == "--add-root") {
+                     gcRoot = absPath(getArg(*arg, arg, end));
+                   } else if (*arg == "--indirect") {
+                     indirectRoot = true;
+                   } else if (*arg == "--no-output") {
+                     noOutput = true;
+                   } else if (*arg != "" && arg->at(0) == '-') {
+                     opFlags.push_back(*arg);
+                     if (*arg == "--max-freed" || *arg == "--max-links" ||
+                         *arg == "--max-atime") { /* !!! hack */
+                       opFlags.push_back(getArg(*arg, arg, end));
+                     }
+                   } else {
+                     opArgs.push_back(*arg);
+                   }
+
+                   if (oldOp && oldOp != op) {
+                     throw UsageError("only one operation may be specified");
+                   }
+
+                   return true;
+                 });
 
     initPlugins();
 
@@ -1209,8 +1274,9 @@ static int _main(int argc, char** argv) {
       throw UsageError("no operation specified");
     }
 
-    if (op != opDump && op != opRestore) /* !!! hack */
+    if (op != opDump && op != opRestore) { /* !!! hack */
       store = openStore();
+    }
 
     op(opFlags, opArgs);
 
diff --git a/third_party/nix/src/nix/build.cc b/third_party/nix/src/nix/build.cc
index 806be2b37a..0738821a89 100644
--- a/third_party/nix/src/nix/build.cc
+++ b/third_party/nix/src/nix/build.cc
@@ -47,8 +47,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand {
     for (size_t i = 0; i < buildables.size(); ++i) {
       auto& b(buildables[i]);
 
-      if (outLink != "")
-        for (auto& output : b.outputs)
+      if (outLink != "") {
+        for (auto& output : b.outputs) {
           if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) {
             std::string symlink = outLink;
             if (i) {
@@ -59,6 +59,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand {
             }
             store2->addPermRoot(output.second, absPath(symlink), true);
           }
+        }
+      }
     }
   }
 };
diff --git a/third_party/nix/src/nix/cat.cc b/third_party/nix/src/nix/cat.cc
index ea9fd0d942..9b2da929ac 100644
--- a/third_party/nix/src/nix/cat.cc
+++ b/third_party/nix/src/nix/cat.cc
@@ -10,10 +10,12 @@ struct MixCat : virtual Args {
 
   void cat(ref<FSAccessor> accessor) {
     auto st = accessor->stat(path);
-    if (st.type == FSAccessor::Type::tMissing)
+    if (st.type == FSAccessor::Type::tMissing) {
       throw Error(format("path '%1%' does not exist") % path);
-    if (st.type != FSAccessor::Type::tRegular)
+    }
+    if (st.type != FSAccessor::Type::tRegular) {
       throw Error(format("path '%1%' is not a regular file") % path);
+    }
 
     std::cout << accessor->readFile(path);
   }
diff --git a/third_party/nix/src/nix/command.cc b/third_party/nix/src/nix/command.cc
index 4c1220668c..b35fb1be98 100644
--- a/third_party/nix/src/nix/command.cc
+++ b/third_party/nix/src/nix/command.cc
@@ -14,10 +14,11 @@ void Command::printHelp(const string& programName, std::ostream& out) {
   if (!exs.empty()) {
     out << "\n";
     out << "Examples:\n";
-    for (auto& ex : exs)
+    for (auto& ex : exs) {
       out << "\n"
           << "  " << ex.description << "\n"  // FIXME: wrap
           << "  $ " << ex.command << "\n";
+    }
   }
 }
 
@@ -26,8 +27,9 @@ MultiCommand::MultiCommand(const Commands& _commands) : commands(_commands) {
       "command", 1, true, [=](std::vector<std::string> ss) {
         assert(!command);
         auto i = commands.find(ss[0]);
-        if (i == commands.end())
+        if (i == commands.end()) {
           throw UsageError("'%s' is not a recognised command", ss[0]);
+        }
         command = i->second;
       }});
 }
@@ -50,8 +52,9 @@ void MultiCommand::printHelp(const string& programName, std::ostream& out) {
   Table2 table;
   for (auto& command : commands) {
     auto descr = command.second->description();
-    if (!descr.empty())
+    if (!descr.empty()) {
       table.push_back(std::make_pair(command.second->name(), descr));
+    }
   }
   printTable(out, table);
 
@@ -72,16 +75,19 @@ bool MultiCommand::processFlag(Strings::iterator& pos, Strings::iterator end) {
 }
 
 bool MultiCommand::processArgs(const Strings& args, bool finish) {
-  if (command)
+  if (command) {
     return command->processArgs(args, finish);
-  else
+  } else {
     return Args::processArgs(args, finish);
+  }
 }
 
 StoreCommand::StoreCommand() {}
 
 ref<Store> StoreCommand::getStore() {
-  if (!_store) _store = createStore();
+  if (!_store) {
+    _store = createStore();
+  }
   return ref<Store>(_store);
 }
 
@@ -90,17 +96,18 @@ ref<Store> StoreCommand::createStore() { return openStore(); }
 void StoreCommand::run() { run(getStore()); }
 
 StorePathsCommand::StorePathsCommand(bool recursive) : recursive(recursive) {
-  if (recursive)
+  if (recursive) {
     mkFlag()
         .longName("no-recursive")
         .description("apply operation to specified paths only")
         .set(&this->recursive, false);
-  else
+  } else {
     mkFlag()
         .longName("recursive")
         .shortName('r')
         .description("apply operation to closure of the specified paths")
         .set(&this->recursive, true);
+  }
 
   mkFlag(0, "all", "apply operation to the entire store", &all);
 }
@@ -109,16 +116,18 @@ void StorePathsCommand::run(ref<Store> store) {
   Paths storePaths;
 
   if (all) {
-    if (installables.size())
+    if (installables.size()) {
       throw UsageError("'--all' does not expect arguments");
+    }
     for (auto& p : store->queryAllValidPaths()) {
       storePaths.push_back(p);
     }
   }
 
   else {
-    for (auto& p : toStorePaths(store, NoBuild, installables))
+    for (auto& p : toStorePaths(store, NoBuild, installables)) {
       storePaths.push_back(p);
+    }
 
     if (recursive) {
       PathSet closure;
@@ -134,8 +143,9 @@ void StorePathsCommand::run(ref<Store> store) {
 void StorePathCommand::run(ref<Store> store) {
   auto storePaths = toStorePaths(store, NoBuild, installables);
 
-  if (storePaths.size() != 1)
+  if (storePaths.size() != 1) {
     throw UsageError("this command requires exactly one store path");
+  }
 
   run(store, *storePaths.begin());
 }
diff --git a/third_party/nix/src/nix/copy.cc b/third_party/nix/src/nix/copy.cc
index fe5e37363c..633fe399b4 100644
--- a/third_party/nix/src/nix/copy.cc
+++ b/third_party/nix/src/nix/copy.cc
@@ -72,8 +72,9 @@ struct CmdCopy : StorePathsCommand {
   }
 
   void run(ref<Store> srcStore, Paths storePaths) override {
-    if (srcUri.empty() && dstUri.empty())
+    if (srcUri.empty() && dstUri.empty()) {
       throw UsageError("you must pass '--from' and/or '--to'");
+    }
 
     ref<Store> dstStore = dstUri.empty() ? openStore() : openStore(dstUri);
 
diff --git a/third_party/nix/src/nix/doctor.cc b/third_party/nix/src/nix/doctor.cc
index cf59aabdbd..44ce2d9292 100644
--- a/third_party/nix/src/nix/doctor.cc
+++ b/third_party/nix/src/nix/doctor.cc
@@ -44,9 +44,11 @@ struct CmdDoctor : StoreCommand {
   bool checkNixInPath() {
     PathSet dirs;
 
-    for (auto& dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
-      if (pathExists(dir + "/nix-env"))
+    for (auto& dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
+      if (pathExists(dir + "/nix-env")) {
         dirs.insert(dirOf(canonPath(dir + "/nix-env", true)));
+      }
+    }
 
     if (dirs.size() != 1) {
       std::cout << "Warning: multiple versions of nix found in PATH."
@@ -73,11 +75,13 @@ struct CmdDoctor : StoreCommand {
         if (store->isStorePath(userEnv) &&
             hasSuffix(userEnv, "user-environment")) {
           while (profileDir.find("/profiles/") == std::string::npos &&
-                 isLink(profileDir))
+                 isLink(profileDir)) {
             profileDir = absPath(readLink(profileDir), dirOf(profileDir));
+          }
 
-          if (profileDir.find("/profiles/") == std::string::npos)
+          if (profileDir.find("/profiles/") == std::string::npos) {
             dirs.insert(dir);
+          }
         }
       } catch (SysError&) {
       }
diff --git a/third_party/nix/src/nix/edit.cc b/third_party/nix/src/nix/edit.cc
index 61d700592b..01c2ec7ef0 100644
--- a/third_party/nix/src/nix/edit.cc
+++ b/third_party/nix/src/nix/edit.cc
@@ -40,8 +40,9 @@ struct CmdEdit : InstallableCommand {
     DLOG(INFO) << "position is " << pos;
 
     auto colon = pos.rfind(':');
-    if (colon == std::string::npos)
+    if (colon == std::string::npos) {
       throw Error("cannot parse meta.position attribute '%s'", pos);
+    }
 
     std::string filename(pos, 0, colon);
     int lineno;
@@ -57,8 +58,9 @@ struct CmdEdit : InstallableCommand {
 
     if (editor.find("emacs") != std::string::npos ||
         editor.find("nano") != std::string::npos ||
-        editor.find("vim") != std::string::npos)
+        editor.find("vim") != std::string::npos) {
       args.push_back(fmt("+%d", lineno));
+    }
 
     args.push_back(filename);
 
diff --git a/third_party/nix/src/nix/eval.cc b/third_party/nix/src/nix/eval.cc
index d84b86bc53..661d587d73 100644
--- a/third_party/nix/src/nix/eval.cc
+++ b/third_party/nix/src/nix/eval.cc
@@ -32,8 +32,9 @@ struct CmdEval : MixJSON, InstallableCommand {
   }
 
   void run(ref<Store> store) override {
-    if (raw && json)
+    if (raw && json) {
       throw UsageError("--raw and --json are mutually exclusive");
+    }
 
     auto state = getEvalState();
 
diff --git a/third_party/nix/src/nix/hash.cc b/third_party/nix/src/nix/hash.cc
index 77be77cfcd..39780532f8 100644
--- a/third_party/nix/src/nix/hash.cc
+++ b/third_party/nix/src/nix/hash.cc
@@ -73,8 +73,9 @@ struct CmdToBase : Command {
   }
 
   void run() override {
-    for (auto s : args)
+    for (auto s : args) {
       std::cout << fmt("%s\n", Hash(s, ht).to_string(base, base == SRI));
+    }
   }
 };
 
@@ -94,29 +95,31 @@ static int compatNixHash(int argc, char** argv) {
 
   parseCmdLine(argc, argv,
                [&](Strings::iterator& arg, const Strings::iterator& end) {
-                 if (*arg == "--help")
+                 if (*arg == "--help") {
                    showManPage("nix-hash");
-                 else if (*arg == "--version")
+                 } else if (*arg == "--version") {
                    printVersion("nix-hash");
-                 else if (*arg == "--flat")
+                 } else if (*arg == "--flat") {
                    flat = true;
-                 else if (*arg == "--base32")
+                 } else if (*arg == "--base32") {
                    base32 = true;
-                 else if (*arg == "--truncate")
+                 } else if (*arg == "--truncate") {
                    truncate = true;
-                 else if (*arg == "--type") {
+                 } else if (*arg == "--type") {
                    string s = getArg(*arg, arg, end);
                    ht = parseHashType(s);
-                   if (ht == htUnknown)
+                   if (ht == htUnknown) {
                      throw UsageError(format("unknown hash type '%1%'") % s);
-                 } else if (*arg == "--to-base16")
+                   }
+                 } else if (*arg == "--to-base16") {
                    op = opTo16;
-                 else if (*arg == "--to-base32")
+                 } else if (*arg == "--to-base32") {
                    op = opTo32;
-                 else if (*arg != "" && arg->at(0) == '-')
+                 } else if (*arg != "" && arg->at(0) == '-') {
                    return false;
-                 else
+                 } else {
                    ss.push_back(*arg);
+                 }
                  return true;
                });
 
diff --git a/third_party/nix/src/nix/installables.cc b/third_party/nix/src/nix/installables.cc
index f400841b7c..8a7de8655b 100644
--- a/third_party/nix/src/nix/installables.cc
+++ b/third_party/nix/src/nix/installables.cc
@@ -30,10 +30,10 @@ Value* SourceExprCommand::getSourceExpr(EvalState& state) {
 
   vSourceExpr = state.allocValue();
 
-  if (file != "")
+  if (file != "") {
     state.evalFile(lookupFileArg(state, file), *vSourceExpr);
 
-  else {
+  } else {
     /* Construct the installation source from $NIX_PATH. */
 
     auto searchPath = state.getSearchPath();
@@ -60,14 +60,18 @@ Value* SourceExprCommand::getSourceExpr(EvalState& state) {
             state.getBuiltin("import"), *v2);
     };
 
-    for (auto& i : searchPath) /* Hack to handle channels. */
+    for (auto& i : searchPath) { /* Hack to handle channels. */
       if (i.first.empty() && pathExists(i.second + "/manifest.nix")) {
-        for (auto& j : readDirectory(i.second))
+        for (auto& j : readDirectory(i.second)) {
           if (j.name != "manifest.nix" &&
-              pathExists(fmt("%s/%s/default.nix", i.second, j.name)))
+              pathExists(fmt("%s/%s/default.nix", i.second, j.name))) {
             addEntry(j.name);
-      } else
+          }
+        }
+      } else {
         addEntry(i.first);
+      }
+    }
 
     vSourceExpr->attrs->sort();
   }
@@ -76,18 +80,20 @@ Value* SourceExprCommand::getSourceExpr(EvalState& state) {
 }
 
 ref<EvalState> SourceExprCommand::getEvalState() {
-  if (!evalState)
+  if (!evalState) {
     evalState = std::make_shared<EvalState>(searchPath, getStore());
+  }
   return ref<EvalState>(evalState);
 }
 
 Buildable Installable::toBuildable() {
   auto buildables = toBuildables();
-  if (buildables.size() != 1)
+  if (buildables.size() != 1) {
     throw Error(
         "installable '%s' evaluates to %d derivations, where only one is "
         "expected",
         what(), buildables.size());
+  }
   return std::move(buildables[0]);
 }
 
@@ -127,9 +133,10 @@ struct InstallableValue : Installable {
       drvPaths.insert(b.drvPath);
 
       auto outputName = drv.queryOutputName();
-      if (outputName == "")
+      if (outputName == "") {
         throw Error("derivation '%s' lacks an 'outputName' attribute",
                     b.drvPath);
+      }
 
       b.outputs.emplace(outputName, drv.queryOutPath());
 
@@ -140,11 +147,13 @@ struct InstallableValue : Installable {
     // merge the buildables.
     if (drvPaths.size() == 1) {
       Buildable b{*drvPaths.begin()};
-      for (auto& b2 : res)
+      for (auto& b2 : res) {
         b.outputs.insert(b2.outputs.begin(), b2.outputs.end());
+      }
       return {b};
-    } else
+    } else {
       return res;
+    }
   }
 };
 
@@ -200,21 +209,23 @@ static std::vector<std::shared_ptr<Installable>> parseInstallables(
   }
 
   for (auto& s : ss) {
-    if (s.compare(0, 1, "(") == 0)
+    if (s.compare(0, 1, "(") == 0) {
       result.push_back(std::make_shared<InstallableExpr>(cmd, s));
 
-    else if (s.find("/") != std::string::npos) {
+    } else if (s.find("/") != std::string::npos) {
       auto path = store->toStorePath(store->followLinksToStore(s));
 
-      if (store->isStorePath(path))
+      if (store->isStorePath(path)) {
         result.push_back(std::make_shared<InstallableStorePath>(path));
+      }
     }
 
-    else if (s == "" || std::regex_match(s, attrPathRegex))
+    else if (s == "" || std::regex_match(s, attrPathRegex)) {
       result.push_back(std::make_shared<InstallableAttrPath>(cmd, s));
 
-    else
+    } else {
       throw UsageError("don't know what to do with argument '%s'", s);
+    }
   }
 
   return result;
@@ -248,10 +259,11 @@ Buildables build(ref<Store> store, RealiseMode mode,
         }
         pathsToBuild.insert(b.drvPath + "!" +
                             concatStringsSep(",", outputNames));
-      } else
+      } else {
         for (auto& output : b.outputs) {
           pathsToBuild.insert(output.second);
         }
+      }
       buildables.push_back(std::move(b));
     }
   }
@@ -269,10 +281,11 @@ PathSet toStorePaths(ref<Store> store, RealiseMode mode,
                      std::vector<std::shared_ptr<Installable>> installables) {
   PathSet outPaths;
 
-  for (auto& b : build(store, mode, installables))
+  for (auto& b : build(store, mode, installables)) {
     for (auto& output : b.outputs) {
       outPaths.insert(output.second);
     }
+  }
 
   return outPaths;
 }
@@ -281,9 +294,10 @@ Path toStorePath(ref<Store> store, RealiseMode mode,
                  std::shared_ptr<Installable> installable) {
   auto paths = toStorePaths(store, mode, {installable});
 
-  if (paths.size() != 1)
+  if (paths.size() != 1) {
     throw Error("argument '%s' should evaluate to one store path",
                 installable->what());
+  }
 
   return *paths.begin();
 }
@@ -293,22 +307,26 @@ PathSet toDerivations(ref<Store> store,
                       bool useDeriver) {
   PathSet drvPaths;
 
-  for (auto& i : installables)
+  for (auto& i : installables) {
     for (auto& b : i->toBuildables()) {
       if (b.drvPath.empty()) {
-        if (!useDeriver)
+        if (!useDeriver) {
           throw Error("argument '%s' did not evaluate to a derivation",
                       i->what());
+        }
         for (auto& output : b.outputs) {
           auto derivers = store->queryValidDerivers(output.second);
-          if (derivers.empty())
+          if (derivers.empty()) {
             throw Error("'%s' does not have a known deriver", i->what());
+          }
           // FIXME: use all derivers?
           drvPaths.insert(*derivers.begin());
         }
-      } else
+      } else {
         drvPaths.insert(b.drvPath);
+      }
     }
+  }
 
   return drvPaths;
 }
diff --git a/third_party/nix/src/nix/ls.cc b/third_party/nix/src/nix/ls.cc
index 62720b93a0..13b7bbbbb9 100644
--- a/third_party/nix/src/nix/ls.cc
+++ b/third_party/nix/src/nix/ls.cc
@@ -35,17 +35,20 @@ struct MixLs : virtual Args, MixJSON {
                                    ? "lrwxrwxrwx"
                                    : "dr-xr-xr-x";
         std::cout << (format("%s %20d %s") % tp % st.fileSize % relPath);
-        if (st.type == FSAccessor::Type::tSymlink)
+        if (st.type == FSAccessor::Type::tSymlink) {
           std::cout << " -> " << accessor->readLink(curPath);
+        }
         std::cout << "\n";
-        if (recursive && st.type == FSAccessor::Type::tDirectory)
+        if (recursive && st.type == FSAccessor::Type::tDirectory) {
           doPath(st, curPath, relPath, false);
+        }
       } else {
         std::cout << relPath << "\n";
         if (recursive) {
           auto st = accessor->stat(curPath);
-          if (st.type == FSAccessor::Type::tDirectory)
+          if (st.type == FSAccessor::Type::tDirectory) {
             doPath(st, curPath, relPath, false);
+          }
         }
       }
     };
@@ -57,8 +60,9 @@ struct MixLs : virtual Args, MixJSON {
         for (auto& name : names) {
           showFile(curPath + "/" + name, relPath + "/" + name);
         }
-      } else
+      } else {
         showFile(curPath, relPath);
+      }
     };
 
     auto st = accessor->stat(path);
diff --git a/third_party/nix/src/nix/main.cc b/third_party/nix/src/nix/main.cc
index 9dbe9b155b..23bc62887a 100644
--- a/third_party/nix/src/nix/main.cc
+++ b/third_party/nix/src/nix/main.cc
@@ -44,8 +44,9 @@ static bool haveInternet() {
       }
     } else if (i->ifa_addr->sa_family == AF_INET6) {
       if (!IN6_IS_ADDR_LOOPBACK(&((sockaddr_in6*)i->ifa_addr)->sin6_addr) &&
-          !IN6_IS_ADDR_LINKLOCAL(&((sockaddr_in6*)i->ifa_addr)->sin6_addr))
+          !IN6_IS_ADDR_LINKLOCAL(&((sockaddr_in6*)i->ifa_addr)->sin6_addr)) {
         return true;
+      }
     }
   }
 
@@ -72,8 +73,9 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs {
           Table2 tbl;
           std::map<std::string, Config::SettingInfo> settings;
           globalConfig.getSettings(settings);
-          for (const auto& s : settings)
+          for (const auto& s : settings) {
             tbl.emplace_back(s.first, s.second.description);
+          }
           printTable(std::cout, tbl);
           throw Exit();
         });
@@ -159,13 +161,15 @@ void mainWrapped(int argc, char** argv) {
     if (!settings.useSubstitutes.overriden) {
       settings.useSubstitutes = false;
     }
-    if (!settings.tarballTtl.overriden)
+    if (!settings.tarballTtl.overriden) {
       settings.tarballTtl = std::numeric_limits<unsigned int>::max();
+    }
     if (!downloadSettings.tries.overriden) {
       downloadSettings.tries = 0;
     }
-    if (!downloadSettings.connectTimeout.overriden)
+    if (!downloadSettings.connectTimeout.overriden) {
       downloadSettings.connectTimeout = 1;
+    }
   }
 
   args.command->prepare();
diff --git a/third_party/nix/src/nix/path-info.cc b/third_party/nix/src/nix/path-info.cc
index 9f155231d4..b871c45f1c 100644
--- a/third_party/nix/src/nix/path-info.cc
+++ b/third_party/nix/src/nix/path-info.cc
@@ -75,8 +75,9 @@ struct CmdPathInfo : StorePathsCommand, MixJSON {
 
   void run(ref<Store> store, Paths storePaths) override {
     size_t pathLen = 0;
-    for (auto& storePath : storePaths)
+    for (auto& storePath : storePaths) {
       pathLen = std::max(pathLen, storePath.size());
+    }
 
     if (json) {
       JSONPlaceholder jsonRoot(std::cout);
@@ -93,9 +94,10 @@ struct CmdPathInfo : StorePathsCommand, MixJSON {
 
         std::cout << storePath;
 
-        if (showSize || showClosureSize || showSigs)
+        if (showSize || showClosureSize || showSigs) {
           std::cout << std::string(
               std::max(0, (int)pathLen - (int)storePath.size()), ' ');
+        }
 
         if (showSize) {
           printSize(info->narSize);
diff --git a/third_party/nix/src/nix/repl.cc b/third_party/nix/src/nix/repl.cc
index f6b62d0ca2..80921f77dc 100644
--- a/third_party/nix/src/nix/repl.cc
+++ b/third_party/nix/src/nix/repl.cc
@@ -181,8 +181,9 @@ static char* completionCallback(char* s, int* match) {
 static int listPossibleCallback(char* s, char*** avp) {
   auto possible = curRepl->completePrefix(s);
 
-  if (possible.size() > (INT_MAX / sizeof(char*)))
+  if (possible.size() > (INT_MAX / sizeof(char*))) {
     throw Error("too many completions");
+  }
 
   int ac = 0;
   char** vp = nullptr;
@@ -190,7 +191,9 @@ static int listPossibleCallback(char* s, char*** avp) {
   auto check = [&](auto* p) {
     if (!p) {
       if (vp) {
-        while (--ac >= 0) free(vp[ac]);
+        while (--ac >= 0) {
+          free(vp[ac]);
+        }
         free(vp);
       }
       throw Error("allocation failure");
@@ -288,20 +291,24 @@ bool NixRepl::getLine(string& input, const std::string& prompt) {
     act.sa_handler = sigintHandler;
     sigfillset(&act.sa_mask);
     act.sa_flags = 0;
-    if (sigaction(SIGINT, &act, &old))
+    if (sigaction(SIGINT, &act, &old)) {
       throw SysError("installing handler for SIGINT");
+    }
 
     sigemptyset(&set);
     sigaddset(&set, SIGINT);
-    if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask))
+    if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask)) {
       throw SysError("unblocking SIGINT");
+    }
   };
   auto restoreSignals = [&]() {
-    if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
+    if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) {
       throw SysError("restoring signals");
+    }
 
-    if (sigaction(SIGINT, &old, 0))
+    if (sigaction(SIGINT, &old, 0)) {
       throw SysError("restoring handler for SIGINT");
+    }
   };
 
   setupSignals();
@@ -343,8 +350,9 @@ StringSet NixRepl::completePrefix(string prefix) {
       auto dir = std::string(cur, 0, slash);
       auto prefix2 = std::string(cur, slash + 1);
       for (auto& entry : readDirectory(dir == "" ? "/" : dir)) {
-        if (entry.name[0] != '.' && hasPrefix(entry.name, prefix2))
+        if (entry.name[0] != '.' && hasPrefix(entry.name, prefix2)) {
           completions.insert(prev + dir + "/" + entry.name);
+        }
       }
     } catch (Error&) {
     }
@@ -417,21 +425,25 @@ bool isVarName(const string& s) {
   if ((c >= '0' && c <= '9') || c == '-' || c == '\'') {
     return false;
   }
-  for (auto& i : s)
+  for (auto& i : s) {
     if (!((i >= 'a' && i <= 'z') || (i >= 'A' && i <= 'Z') ||
-          (i >= '0' && i <= '9') || i == '_' || i == '-' || i == '\''))
+          (i >= '0' && i <= '9') || i == '_' || i == '-' || i == '\'')) {
       return false;
+    }
+  }
   return true;
 }
 
 Path NixRepl::getDerivationPath(Value& v) {
   auto drvInfo = getDerivation(state, v, false);
-  if (!drvInfo)
+  if (!drvInfo) {
     throw Error(
         "expression does not evaluate to a derivation, so I can't build it");
+  }
   Path drvPath = drvInfo->queryDrvPath();
-  if (drvPath == "" || !state.store->isValidPath(drvPath))
+  if (drvPath == "" || !state.store->isValidPath(drvPath)) {
     throw Error("expression did not evaluate to a valid derivation");
+  }
   return drvPath;
 }
 
@@ -520,9 +532,10 @@ bool NixRepl::processLine(string line) {
         std::cout << std::endl
                   << "this derivation produced the following outputs:"
                   << std::endl;
-        for (auto& i : drv.outputs)
+        for (auto& i : drv.outputs) {
           std::cout << format("  %1% -> %2%") % i.first % i.second.path
                     << std::endl;
+        }
       }
     } else if (command == ":i") {
       runProgram(settings.nixBinDir + "/nix-env", Strings{"-i", drvPath});
@@ -537,13 +550,13 @@ bool NixRepl::processLine(string line) {
     printValue(std::cout, v, 1000000000) << std::endl;
   }
 
-  else if (command == ":q" || command == ":quit")
+  else if (command == ":q" || command == ":quit") {
     return false;
 
-  else if (command != "")
+  } else if (command != "") {
     throw Error(format("unknown command '%1%'") % command);
 
-  else {
+  } else {
     size_t p = line.find('=');
     string name;
     if (p != string::npos && p < line.size() && line[p + 1] != '=' &&
@@ -612,8 +625,9 @@ void NixRepl::addAttrsToScope(Value& attrs) {
 }
 
 void NixRepl::addVarToScope(const Symbol& name, Value& v) {
-  if (displ >= envSize)
+  if (displ >= envSize) {
     throw Error("environment full; cannot add more variables");
+  }
   staticEnv.vars[name] = displ;
   env->values[displ++] = &v;
   varNames.insert((string)name);
@@ -638,17 +652,19 @@ std::ostream& NixRepl::printValue(std::ostream& str, Value& v,
 
 std::ostream& printStringValue(std::ostream& str, const char* string) {
   str << "\"";
-  for (const char* i = string; *i; i++)
-    if (*i == '\"' || *i == '\\')
+  for (const char* i = string; *i; i++) {
+    if (*i == '\"' || *i == '\\') {
       str << "\\" << *i;
-    else if (*i == '\n')
+    } else if (*i == '\n') {
       str << "\\n";
-    else if (*i == '\r')
+    } else if (*i == '\r') {
       str << "\\r";
-    else if (*i == '\t')
+    } else if (*i == '\t') {
       str << "\\t";
-    else
+    } else {
       str << *i;
+    }
+  }
   str << "\"";
   return str;
 }
@@ -709,19 +725,21 @@ std::ostream& NixRepl::printValue(std::ostream& str, Value& v,
         }
 
         for (auto& i : sorted) {
-          if (isVarName(i.first))
+          if (isVarName(i.first)) {
             str << i.first;
-          else
+          } else {
             printStringValue(str, i.first.c_str());
+          }
           str << " = ";
-          if (seen.find(i.second) != seen.end())
+          if (seen.find(i.second) != seen.end()) {
             str << "«repeated»";
-          else
+          } else {
             try {
               printValue(str, *i.second, maxDepth - 1, seen);
             } catch (AssertionError& e) {
               str << ESC_RED "«error: " << e.msg() << "»" ESC_END;
             }
+          }
           str << "; ";
         }
 
@@ -741,14 +759,15 @@ std::ostream& NixRepl::printValue(std::ostream& str, Value& v,
       str << "[ ";
       if (maxDepth > 0) {
         for (unsigned int n = 0; n < v.listSize(); ++n) {
-          if (seen.find(v.listElems()[n]) != seen.end())
+          if (seen.find(v.listElems()[n]) != seen.end()) {
             str << "«repeated»";
-          else
+          } else {
             try {
               printValue(str, *v.listElems()[n], maxDepth - 1, seen);
             } catch (AssertionError& e) {
               str << ESC_RED "«error: " << e.msg() << "»" ESC_END;
             }
+          }
           str << " ";
         }
       } else {
diff --git a/third_party/nix/src/nix/run.cc b/third_party/nix/src/nix/run.cc
index 64b883b9a3..523aa87472 100644
--- a/third_party/nix/src/nix/run.cc
+++ b/third_party/nix/src/nix/run.cc
@@ -31,8 +31,9 @@ struct CmdRun : InstallablesCommand {
         .labels({"command", "args"})
         .arity(ArityAny)
         .handler([&](std::vector<std::string> ss) {
-          if (ss.empty())
+          if (ss.empty()) {
             throw UsageError("--command requires at least one argument");
+          }
           command = ss;
         });
 
@@ -87,9 +88,10 @@ struct CmdRun : InstallablesCommand {
     auto accessor = store->getFSAccessor();
 
     if (ignoreEnvironment) {
-      if (!unset.empty())
+      if (!unset.empty()) {
         throw UsageError(
             "--unset does not make sense with --ignore-environment");
+      }
 
       std::map<std::string, std::string> kept;
       for (auto& var : keep) {
@@ -106,9 +108,10 @@ struct CmdRun : InstallablesCommand {
       }
 
     } else {
-      if (!keep.empty())
+      if (!keep.empty()) {
         throw UsageError(
             "--keep does not make sense without --ignore-environment");
+      }
 
       for (auto& var : unset) {
         unsetenv(var.c_str());
@@ -191,17 +194,21 @@ void chrootHelper(int argc, char** argv) {
   std::string realStoreDir = argv[p++];
   std::string cmd = argv[p++];
   Strings args;
-  while (p < argc) args.push_back(argv[p++]);
+  while (p < argc) {
+    args.push_back(argv[p++]);
+  }
 
 #if __linux__
   uid_t uid = getuid();
   uid_t gid = getgid();
 
-  if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == -1)
+  if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == -1) {
     /* Try with just CLONE_NEWNS in case user namespaces are
        specifically disabled. */
-    if (unshare(CLONE_NEWNS) == -1)
+    if (unshare(CLONE_NEWNS) == -1) {
       throw SysError("setting up a private mount namespace");
+    }
+  }
 
   /* Bind-mount realStoreDir on /nix/store. If the latter mount
      point doesn't already exists, we have to create a chroot
@@ -218,8 +225,9 @@ void chrootHelper(int argc, char** argv) {
     createDirs(tmpDir + storeDir);
 
     if (mount(realStoreDir.c_str(), (tmpDir + storeDir).c_str(), "", MS_BIND,
-              0) == -1)
+              0) == -1) {
       throw SysError("mounting '%s' on '%s'", realStoreDir, storeDir);
+    }
 
     for (auto entry : readDirectory("/")) {
       auto src = "/" + entry.name;
@@ -231,10 +239,12 @@ void chrootHelper(int argc, char** argv) {
       if (pathExists(dst)) {
         continue;
       }
-      if (mkdir(dst.c_str(), 0700) == -1)
+      if (mkdir(dst.c_str(), 0700) == -1) {
         throw SysError("creating directory '%s'", dst);
-      if (mount(src.c_str(), dst.c_str(), "", MS_BIND | MS_REC, 0) == -1)
+      }
+      if (mount(src.c_str(), dst.c_str(), "", MS_BIND | MS_REC, 0) == -1) {
         throw SysError("mounting '%s' on '%s'", src, dst);
+      }
     }
 
     char* cwd = getcwd(0, 0);
@@ -243,14 +253,17 @@ void chrootHelper(int argc, char** argv) {
     }
     Finally freeCwd([&]() { free(cwd); });
 
-    if (chroot(tmpDir.c_str()) == -1)
+    if (chroot(tmpDir.c_str()) == -1) {
       throw SysError(format("chrooting into '%s'") % tmpDir);
+    }
 
-    if (chdir(cwd) == -1)
+    if (chdir(cwd) == -1) {
       throw SysError(format("chdir to '%s' in chroot") % cwd);
+    }
   } else if (mount(realStoreDir.c_str(), storeDir.c_str(), "", MS_BIND, 0) ==
-             -1)
+             -1) {
     throw SysError("mounting '%s' on '%s'", realStoreDir, storeDir);
+  }
 
   writeFile("/proc/self/setgroups", "deny");
   writeFile("/proc/self/uid_map", fmt("%d %d %d", uid, uid, 1));
diff --git a/third_party/nix/src/nix/search.cc b/third_party/nix/src/nix/search.cc
index 994fccd564..5978d197fe 100644
--- a/third_party/nix/src/nix/search.cc
+++ b/third_party/nix/src/nix/search.cc
@@ -251,13 +251,15 @@ struct CmdSearch : SourceExprCommand, MixJSON {
       }
 
       if (writeCache &&
-          rename(tmpFile.c_str(), jsonCacheFileName.c_str()) == -1)
+          rename(tmpFile.c_str(), jsonCacheFileName.c_str()) == -1) {
         throw SysError("cannot rename '%s' to '%s'", tmpFile,
                        jsonCacheFileName);
+      }
     }
 
-    if (results.size() == 0)
+    if (results.size() == 0) {
       throw Error("no results for the given search term(s)!");
+    }
 
     RunPager pager;
     for (auto el : results) {
diff --git a/third_party/nix/src/nix/show-config.cc b/third_party/nix/src/nix/show-config.cc
index dba94732a9..85b3c330cd 100644
--- a/third_party/nix/src/nix/show-config.cc
+++ b/third_party/nix/src/nix/show-config.cc
@@ -21,8 +21,9 @@ struct CmdShowConfig : Command, MixJSON {
     } else {
       std::map<std::string, Config::SettingInfo> settings;
       globalConfig.getSettings(settings);
-      for (auto& s : settings)
+      for (auto& s : settings) {
         std::cout << s.first + " = " + s.second.value + "\n";
+      }
     }
   }
 };
diff --git a/third_party/nix/src/nix/sigs.cc b/third_party/nix/src/nix/sigs.cc
index 0eb16b6829..eb99fc8ee5 100644
--- a/third_party/nix/src/nix/sigs.cc
+++ b/third_party/nix/src/nix/sigs.cc
@@ -31,8 +31,9 @@ struct CmdCopySigs : StorePathsCommand {
   }
 
   void run(ref<Store> store, Paths storePaths) override {
-    if (substituterUris.empty())
+    if (substituterUris.empty()) {
       throw UsageError("you must specify at least one substituter using '-s'");
+    }
 
     // FIXME: factor out commonality with MixVerify.
     std::vector<ref<Store>> substituters;
@@ -65,13 +66,15 @@ struct CmdCopySigs : StorePathsCommand {
              binary. */
           if (info->narHash != info2->narHash ||
               info->narSize != info2->narSize ||
-              info->references != info2->references)
+              info->references != info2->references) {
             continue;
+          }
 
-          for (auto& sig : info2->sigs)
+          for (auto& sig : info2->sigs) {
             if (!info->sigs.count(sig)) {
               newSigs.insert(sig);
             }
+          }
         } catch (InvalidPath&) {
         }
       }
@@ -84,8 +87,9 @@ struct CmdCopySigs : StorePathsCommand {
       // logger->incProgress(doneLabel);
     };
 
-    for (auto& storePath : storePaths)
+    for (auto& storePath : storePaths) {
       pool.enqueue(std::bind(doPath, storePath));
+    }
 
     pool.process();
 
@@ -112,8 +116,9 @@ struct CmdSignPaths : StorePathsCommand {
   std::string description() override { return "sign the specified paths"; }
 
   void run(ref<Store> store, Paths storePaths) override {
-    if (secretKeyFile.empty())
+    if (secretKeyFile.empty()) {
       throw UsageError("you must specify a secret key file using '-k'");
+    }
 
     SecretKey secretKey(readFile(secretKeyFile));
 
diff --git a/third_party/nix/src/nix/upgrade-nix.cc b/third_party/nix/src/nix/upgrade-nix.cc
index 277d761ec5..dd11da0087 100644
--- a/third_party/nix/src/nix/upgrade-nix.cc
+++ b/third_party/nix/src/nix/upgrade-nix.cc
@@ -80,8 +80,9 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
       LOG(INFO) << "verifying that '" << storePath << "' works...";
       auto program = storePath + "/bin/nix-env";
       auto s = runProgram(program, false, {"--version"});
-      if (s.find("Nix") == std::string::npos)
+      if (s.find("Nix") == std::string::npos) {
         throw Error("could not verify that '%s' works", program);
+      }
     }
 
     {
@@ -99,15 +100,17 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
   Path getProfileDir(ref<Store> store) {
     Path where;
 
-    for (auto& dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
+    for (auto& dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
       if (pathExists(dir + "/nix-env")) {
         where = dir;
         break;
       }
+    }
 
-    if (where == "")
+    if (where == "") {
       throw Error(
           "couldn't figure out how Nix is installed, so I can't upgrade it");
+    }
 
     LOG(INFO) << "found Nix in '" << where << "'";
 
@@ -119,19 +122,22 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
 
     // Resolve profile to /nix/var/nix/profiles/<name> link.
     while (canonPath(profileDir).find("/profiles/") == std::string::npos &&
-           isLink(profileDir))
+           isLink(profileDir)) {
       profileDir = readLink(profileDir);
+    }
 
     LOG(INFO) << "found profile '" << profileDir << "'";
 
     Path userEnv = canonPath(profileDir, true);
 
-    if (baseNameOf(where) != "bin" || !hasSuffix(userEnv, "user-environment"))
+    if (baseNameOf(where) != "bin" || !hasSuffix(userEnv, "user-environment")) {
       throw Error("directory '%s' does not appear to be part of a Nix profile",
                   where);
+    }
 
-    if (!store->isValidPath(userEnv))
+    if (!store->isValidPath(userEnv)) {
       throw Error("directory '%s' is not in the Nix store", userEnv);
+    }
 
     return profileDir;
   }
diff --git a/third_party/nix/src/nix/verify.cc b/third_party/nix/src/nix/verify.cc
index 3585176ed3..6b74761ba7 100644
--- a/third_party/nix/src/nix/verify.cc
+++ b/third_party/nix/src/nix/verify.cc
@@ -94,10 +94,10 @@ struct CmdVerify : StorePathsCommand {
         if (!noTrust) {
           bool good = false;
 
-          if (info->ultimate && !sigsNeeded)
+          if (info->ultimate && !sigsNeeded) {
             good = true;
 
-          else {
+          } else {
             StringSet sigsSeen;
             size_t actualSigsNeeded = std::max(sigsNeeded, (size_t)1);
             size_t validSigs = 0;
@@ -109,13 +109,15 @@ struct CmdVerify : StorePathsCommand {
                 }
                 sigsSeen.insert(sig);
                 if (validSigs < ValidPathInfo::maxSigs &&
-                    info->checkSignature(publicKeys, sig))
+                    info->checkSignature(publicKeys, sig)) {
                   validSigs++;
+                }
               }
             };
 
-            if (info->isContentAddressed(*store))
+            if (info->isContentAddressed(*store)) {
               validSigs = ValidPathInfo::maxSigs;
+            }
 
             doSigs(info->sigs);
 
@@ -125,8 +127,9 @@ struct CmdVerify : StorePathsCommand {
               }
               try {
                 auto info2 = store2->queryPathInfo(info->path);
-                if (info2->isContentAddressed(*store))
+                if (info2->isContentAddressed(*store)) {
                   validSigs = ValidPathInfo::maxSigs;
+                }
                 doSigs(info2->sigs);
               } catch (InvalidPath&) {
               } catch (Error& e) {
@@ -153,8 +156,9 @@ struct CmdVerify : StorePathsCommand {
       }
     };
 
-    for (auto& storePath : storePaths)
+    for (auto& storePath : storePaths) {
       pool.enqueue(std::bind(doPath, storePath));
+    }
 
     pool.process();
 
diff --git a/third_party/nix/src/nix/why-depends.cc b/third_party/nix/src/nix/why-depends.cc
index 3744f4802a..baf27a6951 100644
--- a/third_party/nix/src/nix/why-depends.cc
+++ b/third_party/nix/src/nix/why-depends.cc
@@ -92,14 +92,16 @@ struct CmdWhyDepends : SourceExprCommand {
 
     std::map<Path, Node> graph;
 
-    for (auto& path : closure)
+    for (auto& path : closure) {
       graph.emplace(path, Node{path, store->queryPathInfo(path)->references});
+    }
 
     // Transpose the graph.
-    for (auto& node : graph)
+    for (auto& node : graph) {
       for (auto& ref : node.second.refs) {
         graph[ref].rrefs.insert(node.first);
       }
+    }
 
     /* Run Dijkstra's shortest path algorithm to get the distance
        of every path in the closure to 'dependency'. */
@@ -146,8 +148,10 @@ struct CmdWhyDepends : SourceExprCommand {
                        node.visited ? "\e[38;5;244m" : "",
                        firstPad != "" ? "=> " : "", node.path);
 
-      if (node.path == dependencyPath && !all && packagePath != dependencyPath)
+      if (node.path == dependencyPath && !all &&
+          packagePath != dependencyPath) {
         throw BailOut();
+      }
 
       if (node.visited) {
         return;
@@ -216,10 +220,11 @@ struct CmdWhyDepends : SourceExprCommand {
 
           for (auto& hash : hashes) {
             auto pos = target.find(hash);
-            if (pos != std::string::npos)
+            if (pos != std::string::npos) {
               hits[hash].emplace_back(
                   fmt("%s -> %s\n", p2,
                       hilite(target, pos, storePathHashLen, getColour(hash))));
+            }
           }
         }
       };