style(3p/nix): Reformat project in Google C++ style r/740

Reformatted with:

    fd . -e hh -e cc | xargs clang-format -i

3 files changed, 1342 insertions, 1405 deletions

diff --git a/third_party/nix/src/nix-env/nix-env.cc b/third_party/nix/src/nix-env/nix-env.cc
index 3292f546ab42..f9a441e8e30b 100644
--- a/third_party/nix/src/nix-env/nix-env.cc
+++ b/third_party/nix/src/nix-env/nix-env.cc
@@ -1,812 +1,749 @@
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <algorithm>
+#include <cerrno>
+#include <ctime>
+#include <iostream>
+#include <sstream>
 #include "attr-path.hh"
 #include "common-eval-args.hh"
 #include "derivations.hh"
 #include "eval.hh"
 #include "get-drvs.hh"
 #include "globals.hh"
+#include "json.hh"
+#include "legacy.hh"
 #include "names.hh"
 #include "profiles.hh"
 #include "shared.hh"
 #include "store-api.hh"
 #include "user-env.hh"
 #include "util.hh"
-#include "json.hh"
 #include "value-to-json.hh"
 #include "xml-writer.hh"
-#include "legacy.hh"
-
-#include <cerrno>
-#include <ctime>
-#include <algorithm>
-#include <iostream>
-#include <sstream>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-
 
 using namespace nix;
 using std::cout;
 
-
 typedef enum {
-    srcNixExprDrvs,
-    srcNixExprs,
-    srcStorePaths,
-    srcProfile,
-    srcAttrPath,
-    srcUnknown
+  srcNixExprDrvs,
+  srcNixExprs,
+  srcStorePaths,
+  srcProfile,
+  srcAttrPath,
+  srcUnknown
 } InstallSourceType;
 
-
-struct InstallSourceInfo
-{
-    InstallSourceType type;
-    Path nixExprPath; /* for srcNixExprDrvs, srcNixExprs */
-    Path profile; /* for srcProfile */
-    string systemFilter; /* for srcNixExprDrvs */
-    Bindings * autoArgs;
+struct InstallSourceInfo {
+  InstallSourceType type;
+  Path nixExprPath;    /* for srcNixExprDrvs, srcNixExprs */
+  Path profile;        /* for srcProfile */
+  string systemFilter; /* for srcNixExprDrvs */
+  Bindings* autoArgs;
 };
 
-
-struct Globals
-{
-    InstallSourceInfo instSource;
-    Path profile;
-    std::shared_ptr<EvalState> state;
-    bool dryRun;
-    bool preserveInstalled;
-    bool removeAll;
-    string forceName;
-    bool prebuiltOnly;
+struct Globals {
+  InstallSourceInfo instSource;
+  Path profile;
+  std::shared_ptr<EvalState> state;
+  bool dryRun;
+  bool preserveInstalled;
+  bool removeAll;
+  string forceName;
+  bool prebuiltOnly;
 };
 
+typedef void (*Operation)(Globals& globals, Strings opFlags, Strings opArgs);
 
-typedef void (* Operation) (Globals & globals,
-    Strings opFlags, Strings opArgs);
-
-
-static string needArg(Strings::iterator & i,
-    Strings & args, const string & arg)
-{
-    if (i == args.end()) throw UsageError(
-        format("'%1%' requires an argument") % arg);
-    return *i++;
+static string needArg(Strings::iterator& i, Strings& args, const string& arg) {
+  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")
-        globals.instSource.type = srcNixExprs;
-    else if (arg == "--from-profile") {
-        globals.instSource.type = srcProfile;
-        globals.instSource.profile = needArg(i, args, arg);
-    }
-    else if (arg == "--attr" || arg == "-A")
-        globals.instSource.type = srcAttrPath;
-    else return false;
-    return true;
+static bool parseInstallSourceOptions(Globals& globals, Strings::iterator& i,
+                                      Strings& args, const string& arg) {
+  if (arg == "--from-expression" || arg == "-E")
+    globals.instSource.type = srcNixExprs;
+  else if (arg == "--from-profile") {
+    globals.instSource.type = srcProfile;
+    globals.instSource.profile = needArg(i, args, arg);
+  } else if (arg == "--attr" || arg == "-A")
+    globals.instSource.type = srcAttrPath;
+  else
+    return false;
+  return true;
 }
 
-
-static bool isNixExpr(const Path & path, struct stat & st)
-{
-    return S_ISREG(st.st_mode) || (S_ISDIR(st.st_mode) && pathExists(path + "/default.nix"));
+static bool isNixExpr(const Path& path, struct stat& st) {
+  return S_ISREG(st.st_mode) ||
+         (S_ISDIR(st.st_mode) && pathExists(path + "/default.nix"));
 }
 
+static void getAllExprs(EvalState& state, const Path& path, StringSet& attrs,
+                        Value& v) {
+  StringSet namesSorted;
+  for (auto& i : readDirectory(path)) namesSorted.insert(i.name);
 
-static void getAllExprs(EvalState & state,
-    const Path & path, StringSet & attrs, Value & v)
-{
-    StringSet namesSorted;
-    for (auto & i : readDirectory(path)) namesSorted.insert(i.name);
-
-    for (auto & i : namesSorted) {
-        /* Ignore the manifest.nix used by profiles.  This is
-           necessary to prevent it from showing up in channels (which
-           are implemented using profiles). */
-        if (i == "manifest.nix") continue;
-
-        Path path2 = path + "/" + i;
-
-        struct stat st;
-        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"))) {
-            /* Strip off the `.nix' filename suffix (if applicable),
-               otherwise the attribute cannot be selected with the
-               `-A' option.  Useful if you want to stick a Nix
-               expression directly in ~/.nix-defexpr. */
-            string attrName = i;
-            if (hasSuffix(attrName, ".nix"))
-                attrName = string(attrName, 0, attrName.size() - 4);
-            if (attrs.find(attrName) != attrs.end()) {
-                printError(format("warning: name collision in input Nix expressions, skipping '%1%'") % path2);
-                continue;
-            }
-            attrs.insert(attrName);
-            /* Load the expression on demand. */
-            Value & vFun = state.getBuiltin("import");
-            Value & vArg(*state.allocValue());
-            mkString(vArg, path2);
-            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))
-            /* `path2' is a directory (with no default.nix in it);
-               recurse into it. */
-            getAllExprs(state, path2, attrs, v);
-    }
-}
+  for (auto& i : namesSorted) {
+    /* Ignore the manifest.nix used by profiles.  This is
+       necessary to prevent it from showing up in channels (which
+       are implemented using profiles). */
+    if (i == "manifest.nix") continue;
 
+    Path path2 = path + "/" + i;
 
-static void loadSourceExpr(EvalState & state, const Path & path, Value & v)
-{
     struct stat st;
-    if (stat(path.c_str(), &st) == -1)
-        throw SysError(format("getting information about '%1%'") % path);
-
-    if (isNixExpr(path, st))
-        state.evalFile(path, v);
-
-    /* The path is a directory.  Put the Nix expressions in the
-       directory in a set, with the file name of each expression as
-       the attribute name.  Recurse into subdirectories (but keep the
-       set flat, not nested, to make it easier for a user to have a
-       ~/.nix-defexpr directory that includes some system-wide
-       directory). */
-    else if (S_ISDIR(st.st_mode)) {
-        state.mkAttrs(v, 1024);
-        state.mkList(*state.allocAttr(v, state.symbols.create("_combineChannels")), 0);
-        StringSet attrs;
-        getAllExprs(state, path, attrs, v);
-        v.attrs->sort();
-    }
-
-    else throw Error("path '%s' is not a directory or a Nix expression", path);
+    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"))) {
+      /* Strip off the `.nix' filename suffix (if applicable),
+         otherwise the attribute cannot be selected with the
+         `-A' option.  Useful if you want to stick a Nix
+         expression directly in ~/.nix-defexpr. */
+      string attrName = i;
+      if (hasSuffix(attrName, ".nix"))
+        attrName = string(attrName, 0, attrName.size() - 4);
+      if (attrs.find(attrName) != attrs.end()) {
+        printError(format("warning: name collision in input Nix expressions, "
+                          "skipping '%1%'") %
+                   path2);
+        continue;
+      }
+      attrs.insert(attrName);
+      /* Load the expression on demand. */
+      Value& vFun = state.getBuiltin("import");
+      Value& vArg(*state.allocValue());
+      mkString(vArg, path2);
+      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))
+      /* `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)
+    throw SysError(format("getting information about '%1%'") % path);
+
+  if (isNixExpr(path, st)) state.evalFile(path, v);
+
+  /* The path is a directory.  Put the Nix expressions in the
+     directory in a set, with the file name of each expression as
+     the attribute name.  Recurse into subdirectories (but keep the
+     set flat, not nested, to make it easier for a user to have a
+     ~/.nix-defexpr directory that includes some system-wide
+     directory). */
+  else if (S_ISDIR(st.st_mode)) {
+    state.mkAttrs(v, 1024);
+    state.mkList(*state.allocAttr(v, state.symbols.create("_combineChannels")),
+                 0);
+    StringSet attrs;
+    getAllExprs(state, path, attrs, v);
+    v.attrs->sort();
+  }
+
+  else
+    throw Error("path '%s' is not a directory or a Nix expression", path);
+}
 
-static void loadDerivations(EvalState & state, Path nixExprPath,
-    string systemFilter, Bindings & autoArgs,
-    const string & pathPrefix, DrvInfos & elems)
-{
-    Value vRoot;
-    loadSourceExpr(state, nixExprPath, vRoot);
+static void loadDerivations(EvalState& state, Path nixExprPath,
+                            string systemFilter, Bindings& autoArgs,
+                            const string& pathPrefix, DrvInfos& elems) {
+  Value vRoot;
+  loadSourceExpr(state, nixExprPath, vRoot);
 
-    Value & v(*findAlongAttrPath(state, pathPrefix, autoArgs, vRoot));
+  Value& v(*findAlongAttrPath(state, pathPrefix, autoArgs, vRoot));
 
-    getDerivations(state, v, pathPrefix, autoArgs, elems, true);
+  getDerivations(state, v, pathPrefix, autoArgs, elems, true);
 
-    /* Filter out all derivations not applicable to the current
-       system. */
-    for (DrvInfos::iterator i = elems.begin(), j; i != elems.end(); i = j) {
-        j = i; j++;
-        if (systemFilter != "*" && i->querySystem() != systemFilter)
-            elems.erase(i);
-    }
+  /* Filter out all derivations not applicable to the current
+     system. */
+  for (DrvInfos::iterator i = elems.begin(), j; i != elems.end(); i = j) {
+    j = i;
+    j++;
+    if (systemFilter != "*" && i->querySystem() != systemFilter) elems.erase(i);
+  }
 }
 
-
-static long getPriority(EvalState & state, DrvInfo & drv)
-{
-    return drv.queryMetaInt("priority", 0);
+static long getPriority(EvalState& state, DrvInfo& drv) {
+  return drv.queryMetaInt("priority", 0);
 }
 
-
-static long comparePriorities(EvalState & state, DrvInfo & drv1, DrvInfo & drv2)
-{
-    return getPriority(state, drv2) - getPriority(state, drv1);
+static long comparePriorities(EvalState& state, DrvInfo& drv1, DrvInfo& drv2) {
+  return getPriority(state, drv2) - getPriority(state, drv1);
 }
 
-
 // FIXME: this function is rather slow since it checks a single path
 // at a time.
-static bool isPrebuilt(EvalState & state, DrvInfo & elem)
-{
-    Path path = elem.queryOutPath();
-    if (state.store->isValidPath(path)) return true;
-    PathSet ps = state.store->querySubstitutablePaths({path});
-    return ps.find(path) != ps.end();
+static bool isPrebuilt(EvalState& state, DrvInfo& elem) {
+  Path path = elem.queryOutPath();
+  if (state.store->isValidPath(path)) return true;
+  PathSet ps = state.store->querySubstitutablePaths({path});
+  return ps.find(path) != ps.end();
 }
 
-
-static void checkSelectorUse(DrvNames & selectors)
-{
-    /* Check that all selectors have been used. */
-    for (auto & i : selectors)
-        if (i.hits == 0 && i.fullName != "*")
-            throw Error(format("selector '%1%' matches no derivations") % i.fullName);
+static void checkSelectorUse(DrvNames& selectors) {
+  /* Check that all selectors have been used. */
+  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,
+                                 const Strings& args, bool newestOnly) {
+  DrvNames selectors = drvNamesFromArgs(args);
+  if (selectors.empty()) selectors.push_back(DrvName("*"));
+
+  DrvInfos elems;
+  set<unsigned int> done;
+
+  for (auto& i : selectors) {
+    typedef list<std::pair<DrvInfo, unsigned int> > Matches;
+    Matches matches;
+    unsigned int n = 0;
+    for (DrvInfos::const_iterator j = allElems.begin(); j != allElems.end();
+         ++j, ++n) {
+      DrvName drvName(j->queryName());
+      if (i.matches(drvName)) {
+        i.hits++;
+        matches.push_back(std::pair<DrvInfo, unsigned int>(*j, n));
+      }
+    }
 
-static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
-    const Strings & args, bool newestOnly)
-{
-    DrvNames selectors = drvNamesFromArgs(args);
-    if (selectors.empty())
-        selectors.push_back(DrvName("*"));
-
-    DrvInfos elems;
-    set<unsigned int> done;
-
-    for (auto & i : selectors) {
-        typedef list<std::pair<DrvInfo, unsigned int> > Matches;
-        Matches matches;
-        unsigned int n = 0;
-        for (DrvInfos::const_iterator j = allElems.begin();
-             j != allElems.end(); ++j, ++n)
-        {
-            DrvName drvName(j->queryName());
-            if (i.matches(drvName)) {
-                i.hits++;
-                matches.push_back(std::pair<DrvInfo, unsigned int>(*j, n));
-            }
+    /* If `newestOnly', if a selector matches multiple derivations
+       with the same name, pick the one matching the current
+       system.  If there are still multiple derivations, pick the
+       one with the highest priority.  If there are still multiple
+       derivations, pick the one with the highest version.
+       Finally, if there are still multiple derivations,
+       arbitrarily pick the first one. */
+    if (newestOnly) {
+      /* Map from package names to derivations. */
+      typedef map<string, std::pair<DrvInfo, unsigned int> > Newest;
+      Newest newest;
+      StringSet multiple;
+
+      for (auto& j : matches) {
+        DrvName drvName(j.first.queryName());
+        long d = 1;
+
+        Newest::iterator k = newest.find(drvName.name);
+
+        if (k != newest.end()) {
+          d = j.first.querySystem() == k->second.first.querySystem()
+                  ? 0
+                  : j.first.querySystem() == settings.thisSystem
+                        ? 1
+                        : k->second.first.querySystem() == settings.thisSystem
+                              ? -1
+                              : 0;
+          if (d == 0) d = comparePriorities(state, j.first, k->second.first);
+          if (d == 0)
+            d = compareVersions(drvName.version,
+                                DrvName(k->second.first.queryName()).version);
         }
 
-        /* If `newestOnly', if a selector matches multiple derivations
-           with the same name, pick the one matching the current
-           system.  If there are still multiple derivations, pick the
-           one with the highest priority.  If there are still multiple
-           derivations, pick the one with the highest version.
-           Finally, if there are still multiple derivations,
-           arbitrarily pick the first one. */
-        if (newestOnly) {
-
-            /* Map from package names to derivations. */
-            typedef map<string, std::pair<DrvInfo, unsigned int> > Newest;
-            Newest newest;
-            StringSet multiple;
-
-            for (auto & j : matches) {
-                DrvName drvName(j.first.queryName());
-                long d = 1;
-
-                Newest::iterator k = newest.find(drvName.name);
-
-                if (k != newest.end()) {
-                    d = j.first.querySystem() == k->second.first.querySystem() ? 0 :
-                        j.first.querySystem() == settings.thisSystem ? 1 :
-                        k->second.first.querySystem() == settings.thisSystem ? -1 : 0;
-                    if (d == 0)
-                        d = comparePriorities(state, j.first, k->second.first);
-                    if (d == 0)
-                        d = compareVersions(drvName.version, DrvName(k->second.first.queryName()).version);
-                }
-
-                if (d > 0) {
-                    newest.erase(drvName.name);
-                    newest.insert(Newest::value_type(drvName.name, j));
-                    multiple.erase(j.first.queryName());
-                } else if (d == 0) {
-                    multiple.insert(j.first.queryName());
-                }
-            }
-
-            matches.clear();
-            for (auto & j : newest) {
-                if (multiple.find(j.second.first.queryName()) != multiple.end())
-                    printInfo(
-                        "warning: there are multiple derivations named '%1%'; using the first one",
-                        j.second.first.queryName());
-                matches.push_back(j.second);
-            }
+        if (d > 0) {
+          newest.erase(drvName.name);
+          newest.insert(Newest::value_type(drvName.name, j));
+          multiple.erase(j.first.queryName());
+        } else if (d == 0) {
+          multiple.insert(j.first.queryName());
         }
-
-        /* Insert only those elements in the final list that we
-           haven't inserted before. */
-        for (auto & j : matches)
-            if (done.find(j.second) == done.end()) {
-                done.insert(j.second);
-                elems.push_back(j.first);
-            }
+      }
+
+      matches.clear();
+      for (auto& j : newest) {
+        if (multiple.find(j.second.first.queryName()) != multiple.end())
+          printInfo(
+              "warning: there are multiple derivations named '%1%'; using the "
+              "first one",
+              j.second.first.queryName());
+        matches.push_back(j.second);
+      }
     }
 
-    checkSelectorUse(selectors);
+    /* Insert only those elements in the final list that we
+       haven't inserted before. */
+    for (auto& j : matches)
+      if (done.find(j.second) == done.end()) {
+        done.insert(j.second);
+        elems.push_back(j.first);
+      }
+  }
 
-    return elems;
-}
+  checkSelectorUse(selectors);
 
-
-static bool isPath(const string & s)
-{
-    return s.find('/') != string::npos;
+  return elems;
 }
 
+static bool isPath(const string& s) { return s.find('/') != string::npos; }
+
+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()))
+    type = srcStorePaths;
+
+  switch (type) {
+    /* Get the available user environment elements from the
+       derivations specified in a Nix expression, including only
+       those with names matching any of the names in `args'. */
+    case srcUnknown:
+    case srcNixExprDrvs: {
+      /* Load the derivations from the (default or specified)
+         Nix expression. */
+      DrvInfos allElems;
+      loadDerivations(state, instSource.nixExprPath, instSource.systemFilter,
+                      *instSource.autoArgs, "", allElems);
+
+      elems = filterBySelector(state, allElems, args, newestOnly);
+
+      break;
+    }
 
-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()))
-        type = srcStorePaths;
-
-    switch (type) {
-
-        /* Get the available user environment elements from the
-           derivations specified in a Nix expression, including only
-           those with names matching any of the names in `args'. */
-        case srcUnknown:
-        case srcNixExprDrvs: {
-
-            /* Load the derivations from the (default or specified)
-               Nix expression. */
-            DrvInfos allElems;
-            loadDerivations(state, instSource.nixExprPath,
-                instSource.systemFilter, *instSource.autoArgs, "", allElems);
-
-            elems = filterBySelector(state, allElems, args, newestOnly);
-
-            break;
-        }
-
-        /* Get the available user environment elements from the Nix
-           expressions specified on the command line; these should be
-           functions that take the default Nix expression file as
-           argument, e.g., if the file is `./foo.nix', then the
-           argument `x: x.bar' is equivalent to `(x: x.bar)
-           (import ./foo.nix)' = `(import ./foo.nix).bar'. */
-        case srcNixExprs: {
-
-            Value vArg;
-            loadSourceExpr(state, instSource.nixExprPath, vArg);
-
-            for (auto & i : args) {
-                Expr * eFun = state.parseExprFromString(i, absPath("."));
-                Value vFun, vTmp;
-                state.eval(eFun, vFun);
-                mkApp(vTmp, vFun, vArg);
-                getDerivations(state, vTmp, "", *instSource.autoArgs, elems, true);
-            }
-
-            break;
-        }
-
-        /* The available user environment elements are specified as a
-           list of store paths (which may or may not be
-           derivations). */
-        case srcStorePaths: {
-
-            for (auto & i : args) {
-                Path path = state.store->followLinksToStorePath(i);
-
-                string name = baseNameOf(path);
-                string::size_type dash = name.find('-');
-                if (dash != string::npos)
-                    name = string(name, dash + 1);
-
-                DrvInfo elem(state, "", nullptr);
-                elem.setName(name);
-
-                if (isDerivation(path)) {
-                    elem.setDrvPath(path);
-                    elem.setOutPath(state.store->derivationFromPath(path).findOutput("out"));
-                    if (name.size() >= drvExtension.size() &&
-                        string(name, name.size() - drvExtension.size()) == drvExtension)
-                        name = string(name, 0, name.size() - drvExtension.size());
-                }
-                else elem.setOutPath(path);
-
-                elems.push_back(elem);
-            }
-
-            break;
-        }
-
-        /* Get the available user environment elements from another
-           user environment.  These are then filtered as in the
-           `srcNixExprDrvs' case. */
-        case srcProfile: {
-            elems = filterBySelector(state,
-                queryInstalled(state, instSource.profile),
-                args, newestOnly);
-            break;
-        }
-
-        case srcAttrPath: {
-            Value vRoot;
-            loadSourceExpr(state, instSource.nixExprPath, vRoot);
-            for (auto & i : args) {
-                Value & v(*findAlongAttrPath(state, i, *instSource.autoArgs, vRoot));
-                getDerivations(state, v, "", *instSource.autoArgs, elems, true);
-            }
-            break;
-        }
+    /* Get the available user environment elements from the Nix
+       expressions specified on the command line; these should be
+       functions that take the default Nix expression file as
+       argument, e.g., if the file is `./foo.nix', then the
+       argument `x: x.bar' is equivalent to `(x: x.bar)
+       (import ./foo.nix)' = `(import ./foo.nix).bar'. */
+    case srcNixExprs: {
+      Value vArg;
+      loadSourceExpr(state, instSource.nixExprPath, vArg);
+
+      for (auto& i : args) {
+        Expr* eFun = state.parseExprFromString(i, absPath("."));
+        Value vFun, vTmp;
+        state.eval(eFun, vFun);
+        mkApp(vTmp, vFun, vArg);
+        getDerivations(state, vTmp, "", *instSource.autoArgs, elems, true);
+      }
+
+      break;
     }
-}
 
+    /* The available user environment elements are specified as a
+       list of store paths (which may or may not be
+       derivations). */
+    case srcStorePaths: {
+      for (auto& i : args) {
+        Path path = state.store->followLinksToStorePath(i);
+
+        string name = baseNameOf(path);
+        string::size_type dash = name.find('-');
+        if (dash != string::npos) name = string(name, dash + 1);
+
+        DrvInfo elem(state, "", nullptr);
+        elem.setName(name);
+
+        if (isDerivation(path)) {
+          elem.setDrvPath(path);
+          elem.setOutPath(
+              state.store->derivationFromPath(path).findOutput("out"));
+          if (name.size() >= drvExtension.size() &&
+              string(name, name.size() - drvExtension.size()) == drvExtension)
+            name = string(name, 0, name.size() - drvExtension.size());
+        } else
+          elem.setOutPath(path);
+
+        elems.push_back(elem);
+      }
+
+      break;
+    }
 
-static void printMissing(EvalState & state, DrvInfos & elems)
-{
-    PathSet targets;
-    for (auto & i : elems) {
-        Path drvPath = i.queryDrvPath();
-        if (drvPath != "")
-            targets.insert(drvPath);
-        else
-            targets.insert(i.queryOutPath());
+    /* Get the available user environment elements from another
+       user environment.  These are then filtered as in the
+       `srcNixExprDrvs' case. */
+    case srcProfile: {
+      elems = filterBySelector(state, queryInstalled(state, instSource.profile),
+                               args, newestOnly);
+      break;
     }
 
-    printMissing(state.store, targets);
+    case srcAttrPath: {
+      Value vRoot;
+      loadSourceExpr(state, instSource.nixExprPath, vRoot);
+      for (auto& i : args) {
+        Value& v(*findAlongAttrPath(state, i, *instSource.autoArgs, vRoot));
+        getDerivations(state, v, "", *instSource.autoArgs, elems, true);
+      }
+      break;
+    }
+  }
 }
 
-
-static bool keep(DrvInfo & drv)
-{
-    return drv.queryMetaBool("keep", false);
+static void printMissing(EvalState& state, DrvInfos& elems) {
+  PathSet targets;
+  for (auto& i : elems) {
+    Path drvPath = i.queryDrvPath();
+    if (drvPath != "")
+      targets.insert(drvPath);
+    else
+      targets.insert(i.queryOutPath());
+  }
+
+  printMissing(state.store, targets);
 }
 
+static bool keep(DrvInfo& drv) { return drv.queryMetaBool("keep", false); }
+
+static void installDerivations(Globals& globals, const Strings& args,
+                               const Path& profile) {
+  debug(format("installing derivations"));
+
+  /* Get the set of user environment elements to be installed. */
+  DrvInfos newElems, newElemsTmp;
+  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))
+      newElems.push_back(i);
+
+  StringSet newNames;
+  for (auto& i : newElems) {
+    /* `forceName' is a hack to get package names right in some
+       one-click installs, namely those where the name used in the
+       path is not the one we want (e.g., `java-front' versus
+       `java-front-0.9pre15899'). */
+    if (globals.forceName != "") i.setName(globals.forceName);
+    newNames.insert(DrvName(i.queryName()).name);
+  }
+
+  while (true) {
+    string lockToken = optimisticLockProfile(profile);
+
+    DrvInfos allElems(newElems);
+
+    /* Add in the already installed derivations, unless they have
+       the same name as a to-be-installed element. */
+    if (!globals.removeAll) {
+      DrvInfos installedElems = queryInstalled(*globals.state, profile);
+
+      for (auto& i : installedElems) {
+        DrvName drvName(i.queryName());
+        if (!globals.preserveInstalled &&
+            newNames.find(drvName.name) != newNames.end() && !keep(i))
+          printInfo("replacing old '%s'", i.queryName());
+        else
+          allElems.push_back(i);
+      }
 
-static void installDerivations(Globals & globals,
-    const Strings & args, const Path & profile)
-{
-    debug(format("installing derivations"));
-
-    /* Get the set of user environment elements to be installed. */
-    DrvInfos newElems, newElemsTmp;
-    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))
-            newElems.push_back(i);
-
-    StringSet newNames;
-    for (auto & i : newElems) {
-        /* `forceName' is a hack to get package names right in some
-           one-click installs, namely those where the name used in the
-           path is not the one we want (e.g., `java-front' versus
-           `java-front-0.9pre15899'). */
-        if (globals.forceName != "")
-            i.setName(globals.forceName);
-        newNames.insert(DrvName(i.queryName()).name);
+      for (auto& i : newElems) printInfo("installing '%s'", i.queryName());
     }
 
+    printMissing(*globals.state, newElems);
 
-    while (true) {
-        string lockToken = optimisticLockProfile(profile);
-
-        DrvInfos allElems(newElems);
-
-        /* Add in the already installed derivations, unless they have
-           the same name as a to-be-installed element. */
-        if (!globals.removeAll) {
-            DrvInfos installedElems = queryInstalled(*globals.state, profile);
-
-            for (auto & i : installedElems) {
-                DrvName drvName(i.queryName());
-                if (!globals.preserveInstalled &&
-                    newNames.find(drvName.name) != newNames.end() &&
-                    !keep(i))
-                    printInfo("replacing old '%s'", i.queryName());
-                else
-                    allElems.push_back(i);
-            }
-
-            for (auto & i : newElems)
-                printInfo("installing '%s'", i.queryName());
-        }
-
-        printMissing(*globals.state, newElems);
-
-        if (globals.dryRun) return;
+    if (globals.dryRun) return;
 
-        if (createUserEnv(*globals.state, allElems,
-                profile, settings.envKeepDerivations, lockToken)) break;
-    }
+    if (createUserEnv(*globals.state, allElems, profile,
+                      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)) ;
-        else if (arg == "--preserve-installed" || arg == "-P")
-            globals.preserveInstalled = true;
-        else if (arg == "--remove-all" || arg == "-r")
-            globals.removeAll = true;
-        else throw UsageError(format("unknown flag '%1%'") % arg);
-    }
-
-    installDerivations(globals, opArgs, globals.profile);
+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))
+      ;
+    else if (arg == "--preserve-installed" || arg == "-P")
+      globals.preserveInstalled = true;
+    else if (arg == "--remove-all" || arg == "-r")
+      globals.removeAll = true;
+    else
+      throw UsageError(format("unknown flag '%1%'") % arg);
+  }
+
+  installDerivations(globals, opArgs, globals.profile);
 }
 
-
 typedef enum { utLt, utLeq, utEq, utAlways } UpgradeType;
 
+static void upgradeDerivations(Globals& globals, const Strings& args,
+                               UpgradeType upgradeType) {
+  debug(format("upgrading derivations"));
 
-static void upgradeDerivations(Globals & globals,
-    const Strings & args, UpgradeType upgradeType)
-{
-    debug(format("upgrading derivations"));
-
-    /* Upgrade works as follows: we take all currently installed
-       derivations, and for any derivation matching any selector, look
-       for a derivation in the input Nix expression that has the same
-       name and a higher version number. */
-
-    while (true) {
-        string lockToken = optimisticLockProfile(globals.profile);
+  /* Upgrade works as follows: we take all currently installed
+     derivations, and for any derivation matching any selector, look
+     for a derivation in the input Nix expression that has the same
+     name and a higher version number. */
 
-        DrvInfos installedElems = queryInstalled(*globals.state, globals.profile);
+  while (true) {
+    string lockToken = optimisticLockProfile(globals.profile);
 
-        /* Fetch all derivations from the input file. */
-        DrvInfos availElems;
-        queryInstSources(*globals.state, globals.instSource, args, availElems, false);
+    DrvInfos installedElems = queryInstalled(*globals.state, globals.profile);
 
-        /* Go through all installed derivations. */
-        DrvInfos newElems;
-        for (auto & i : installedElems) {
-            DrvName drvName(i.queryName());
+    /* Fetch all derivations from the input file. */
+    DrvInfos availElems;
+    queryInstSources(*globals.state, globals.instSource, args, availElems,
+                     false);
 
-            try {
+    /* Go through all installed derivations. */
+    DrvInfos newElems;
+    for (auto& i : installedElems) {
+      DrvName drvName(i.queryName());
 
-                if (keep(i)) {
-                    newElems.push_back(i);
-                    continue;
-                }
-
-                /* Find the derivation in the input Nix expression
-                   with the same name that satisfies the version
-                   constraints specified by upgradeType.  If there are
-                   multiple matches, take the one with the highest
-                   priority.  If there are still multiple matches,
-                   take the one with the highest version.
-                   Do not upgrade if it would decrease the priority. */
-                DrvInfos::iterator bestElem = availElems.end();
-                string bestVersion;
-                for (auto j = availElems.begin(); j != availElems.end(); ++j) {
-                    if (comparePriorities(*globals.state, i, *j) > 0)
-                        continue;
-                    DrvName newName(j->queryName());
-                    if (newName.name == drvName.name) {
-                        int d = compareVersions(drvName.version, newName.version);
-                        if ((upgradeType == utLt && d < 0) ||
-                            (upgradeType == utLeq && d <= 0) ||
-                            (upgradeType == utEq && d == 0) ||
-                            upgradeType == utAlways)
-                        {
-                            long d2 = -1;
-                            if (bestElem != availElems.end()) {
-                                d2 = comparePriorities(*globals.state, *bestElem, *j);
-                                if (d2 == 0) d2 = compareVersions(bestVersion, newName.version);
-                            }
-                            if (d2 < 0 && (!globals.prebuiltOnly || isPrebuilt(*globals.state, *j))) {
-                                bestElem = j;
-                                bestVersion = newName.version;
-                            }
-                        }
-                    }
-                }
+      try {
+        if (keep(i)) {
+          newElems.push_back(i);
+          continue;
+        }
 
-                if (bestElem != availElems.end() &&
-                    i.queryOutPath() !=
-                    bestElem->queryOutPath())
-                {
-                    const char * action = compareVersions(drvName.version, bestVersion) <= 0
-                        ? "upgrading" : "downgrading";
-                    printInfo("%1% '%2%' to '%3%'",
-                        action, i.queryName(), bestElem->queryName());
-                    newElems.push_back(*bestElem);
-                } else newElems.push_back(i);
-
-            } catch (Error & e) {
-                e.addPrefix(fmt("while trying to find an upgrade for '%s':\n", i.queryName()));
-                throw;
+        /* Find the derivation in the input Nix expression
+           with the same name that satisfies the version
+           constraints specified by upgradeType.  If there are
+           multiple matches, take the one with the highest
+           priority.  If there are still multiple matches,
+           take the one with the highest version.
+           Do not upgrade if it would decrease the priority. */
+        DrvInfos::iterator bestElem = availElems.end();
+        string bestVersion;
+        for (auto j = availElems.begin(); j != availElems.end(); ++j) {
+          if (comparePriorities(*globals.state, i, *j) > 0) continue;
+          DrvName newName(j->queryName());
+          if (newName.name == drvName.name) {
+            int d = compareVersions(drvName.version, newName.version);
+            if ((upgradeType == utLt && d < 0) ||
+                (upgradeType == utLeq && d <= 0) ||
+                (upgradeType == utEq && d == 0) || upgradeType == utAlways) {
+              long d2 = -1;
+              if (bestElem != availElems.end()) {
+                d2 = comparePriorities(*globals.state, *bestElem, *j);
+                if (d2 == 0) d2 = compareVersions(bestVersion, newName.version);
+              }
+              if (d2 < 0 &&
+                  (!globals.prebuiltOnly || isPrebuilt(*globals.state, *j))) {
+                bestElem = j;
+                bestVersion = newName.version;
+              }
             }
+          }
         }
 
-        printMissing(*globals.state, newElems);
-
-        if (globals.dryRun) return;
-
-        if (createUserEnv(*globals.state, newElems,
-                globals.profile, settings.envKeepDerivations, lockToken)) break;
+        if (bestElem != availElems.end() &&
+            i.queryOutPath() != bestElem->queryOutPath()) {
+          const char* action =
+              compareVersions(drvName.version, bestVersion) <= 0
+                  ? "upgrading"
+                  : "downgrading";
+          printInfo("%1% '%2%' to '%3%'", action, i.queryName(),
+                    bestElem->queryName());
+          newElems.push_back(*bestElem);
+        } else
+          newElems.push_back(i);
+
+      } catch (Error& e) {
+        e.addPrefix(
+            fmt("while trying to find an upgrade for '%s':\n", i.queryName()));
+        throw;
+      }
     }
-}
 
+    printMissing(*globals.state, newElems);
 
-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)) ;
-        else if (arg == "--lt") upgradeType = utLt;
-        else if (arg == "--leq") upgradeType = utLeq;
-        else if (arg == "--eq") upgradeType = utEq;
-        else if (arg == "--always") upgradeType = utAlways;
-        else throw UsageError(format("unknown flag '%1%'") % arg);
-    }
+    if (globals.dryRun) return;
 
-    upgradeDerivations(globals, opArgs, upgradeType);
+    if (createUserEnv(*globals.state, newElems, globals.profile,
+                      settings.envKeepDerivations, lockToken))
+      break;
+  }
 }
 
-
-static void setMetaFlag(EvalState & state, DrvInfo & drv,
-    const string & name, const string & value)
-{
-    Value * v = state.allocValue();
-    mkString(*v, value.c_str());
-    drv.setMeta(name, v);
+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))
+      ;
+    else if (arg == "--lt")
+      upgradeType = utLt;
+    else if (arg == "--leq")
+      upgradeType = utLeq;
+    else if (arg == "--eq")
+      upgradeType = utEq;
+    else if (arg == "--always")
+      upgradeType = utAlways;
+    else
+      throw UsageError(format("unknown flag '%1%'") % arg);
+  }
+
+  upgradeDerivations(globals, opArgs, upgradeType);
 }
 
+static void setMetaFlag(EvalState& state, DrvInfo& drv, const string& name,
+                        const string& value) {
+  Value* v = state.allocValue();
+  mkString(*v, value.c_str());
+  drv.setMeta(name, v);
+}
 
-static void opSetFlag(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    if (opArgs.size() < 2)
-        throw UsageError("not enough arguments to '--set-flag'");
-
-    Strings::iterator arg = opArgs.begin();
-    string flagName = *arg++;
-    string flagValue = *arg++;
-    DrvNames selectors = drvNamesFromArgs(Strings(arg, opArgs.end()));
-
-    while (true) {
-        string lockToken = optimisticLockProfile(globals.profile);
-
-        DrvInfos installedElems = queryInstalled(*globals.state, globals.profile);
-
-        /* Update all matching derivations. */
-        for (auto & i : installedElems) {
-            DrvName drvName(i.queryName());
-            for (auto & j : selectors)
-                if (j.matches(drvName)) {
-                    printInfo("setting flag on '%1%'", i.queryName());
-                    j.hits++;
-                    setMetaFlag(*globals.state, i, flagName, flagValue);
-                    break;
-                }
+static void opSetFlag(Globals& globals, Strings opFlags, Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  if (opArgs.size() < 2)
+    throw UsageError("not enough arguments to '--set-flag'");
+
+  Strings::iterator arg = opArgs.begin();
+  string flagName = *arg++;
+  string flagValue = *arg++;
+  DrvNames selectors = drvNamesFromArgs(Strings(arg, opArgs.end()));
+
+  while (true) {
+    string lockToken = optimisticLockProfile(globals.profile);
+
+    DrvInfos installedElems = queryInstalled(*globals.state, globals.profile);
+
+    /* Update all matching derivations. */
+    for (auto& i : installedElems) {
+      DrvName drvName(i.queryName());
+      for (auto& j : selectors)
+        if (j.matches(drvName)) {
+          printInfo("setting flag on '%1%'", i.queryName());
+          j.hits++;
+          setMetaFlag(*globals.state, i, flagName, flagValue);
+          break;
         }
+    }
 
-        checkSelectorUse(selectors);
+    checkSelectorUse(selectors);
 
-        /* Write the new user environment. */
-        if (createUserEnv(*globals.state, installedElems,
-                globals.profile, settings.envKeepDerivations, lockToken)) break;
-    }
+    /* Write the new user environment. */
+    if (createUserEnv(*globals.state, installedElems, globals.profile,
+                      settings.envKeepDerivations, lockToken))
+      break;
+  }
 }
 
+static void opSet(Globals& globals, Strings opFlags, Strings opArgs) {
+  auto store2 = globals.state->store.dynamic_pointer_cast<LocalFSStore>();
+  if (!store2) throw Error("--set is not supported for this Nix store");
 
-static void opSet(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    auto store2 = globals.state->store.dynamic_pointer_cast<LocalFSStore>();
-    if (!store2) throw Error("--set is not supported for this Nix store");
+  for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
+    string arg = *i++;
+    if (parseInstallSourceOptions(globals, i, opFlags, arg))
+      ;
+    else
+      throw UsageError(format("unknown flag '%1%'") % arg);
+  }
 
-    for (Strings::iterator i = opFlags.begin(); i != opFlags.end(); ) {
-        string arg = *i++;
-        if (parseInstallSourceOptions(globals, i, opFlags, arg)) ;
-        else throw UsageError(format("unknown flag '%1%'") % arg);
-    }
-
-    DrvInfos elems;
-    queryInstSources(*globals.state, globals.instSource, opArgs, elems, true);
+  DrvInfos elems;
+  queryInstSources(*globals.state, globals.instSource, opArgs, elems, true);
 
-    if (elems.size() != 1)
-        throw Error("--set requires exactly one derivation");
+  if (elems.size() != 1) throw Error("--set requires exactly one derivation");
 
-    DrvInfo & drv(elems.front());
+  DrvInfo& drv(elems.front());
 
-    if (globals.forceName != "")
-        drv.setName(globals.forceName);
+  if (globals.forceName != "") drv.setName(globals.forceName);
 
-    if (drv.queryDrvPath() != "") {
-        PathSet paths = {drv.queryDrvPath()};
-        printMissing(globals.state->store, paths);
-        if (globals.dryRun) return;
-        globals.state->store->buildPaths(paths, globals.state->repair ? bmRepair : bmNormal);
-    }
-    else {
-        printMissing(globals.state->store, {drv.queryOutPath()});
-        if (globals.dryRun) return;
-        globals.state->store->ensurePath(drv.queryOutPath());
-    }
+  if (drv.queryDrvPath() != "") {
+    PathSet paths = {drv.queryDrvPath()};
+    printMissing(globals.state->store, paths);
+    if (globals.dryRun) return;
+    globals.state->store->buildPaths(
+        paths, globals.state->repair ? bmRepair : bmNormal);
+  } else {
+    printMissing(globals.state->store, {drv.queryOutPath()});
+    if (globals.dryRun) return;
+    globals.state->store->ensurePath(drv.queryOutPath());
+  }
 
-    debug(format("switching to new user environment"));
-    Path generation = createGeneration(ref<LocalFSStore>(store2), globals.profile, drv.queryOutPath());
-    switchLink(globals.profile, generation);
+  debug(format("switching to new user environment"));
+  Path generation = createGeneration(ref<LocalFSStore>(store2), globals.profile,
+                                     drv.queryOutPath());
+  switchLink(globals.profile, generation);
 }
 
-
-static void uninstallDerivations(Globals & globals, Strings & selectors,
-    Path & profile)
-{
-    while (true) {
-        string lockToken = optimisticLockProfile(profile);
-
-        DrvInfos installedElems = queryInstalled(*globals.state, profile);
-        DrvInfos newElems;
-
-        for (auto & i : installedElems) {
-            DrvName drvName(i.queryName());
-            bool found = false;
-            for (auto & j : selectors)
-                /* !!! the repeated calls to followLinksToStorePath()
-                   are expensive, should pre-compute them. */
-                if ((isPath(j) && i.queryOutPath() == globals.state->store->followLinksToStorePath(j))
-                    || DrvName(j).matches(drvName))
-                {
-                    printInfo("uninstalling '%s'", i.queryName());
-                    found = true;
-                    break;
-                }
-            if (!found) newElems.push_back(i);
+static void uninstallDerivations(Globals& globals, Strings& selectors,
+                                 Path& profile) {
+  while (true) {
+    string lockToken = optimisticLockProfile(profile);
+
+    DrvInfos installedElems = queryInstalled(*globals.state, profile);
+    DrvInfos newElems;
+
+    for (auto& i : installedElems) {
+      DrvName drvName(i.queryName());
+      bool found = false;
+      for (auto& j : selectors)
+        /* !!! the repeated calls to followLinksToStorePath()
+           are expensive, should pre-compute them. */
+        if ((isPath(j) &&
+             i.queryOutPath() ==
+                 globals.state->store->followLinksToStorePath(j)) ||
+            DrvName(j).matches(drvName)) {
+          printInfo("uninstalling '%s'", i.queryName());
+          found = true;
+          break;
         }
-
-        if (globals.dryRun) return;
-
-        if (createUserEnv(*globals.state, newElems,
-                profile, settings.envKeepDerivations, lockToken)) break;
+      if (!found) newElems.push_back(i);
     }
-}
 
+    if (globals.dryRun) return;
 
-static void opUninstall(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    uninstallDerivations(globals, opArgs, globals.profile);
+    if (createUserEnv(*globals.state, newElems, profile,
+                      settings.envKeepDerivations, lockToken))
+      break;
+  }
 }
 
-
-static bool cmpChars(char a, char b)
-{
-    return toupper(a) < toupper(b);
+static void opUninstall(Globals& globals, Strings opFlags, Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  uninstallDerivations(globals, opArgs, globals.profile);
 }
 
+static bool cmpChars(char a, char b) { return toupper(a) < toupper(b); }
 
-static bool cmpElemByName(const DrvInfo & a, const DrvInfo & b)
-{
-    auto a_name = a.queryName();
-    auto b_name = b.queryName();
-    return lexicographical_compare(
-        a_name.begin(), a_name.end(),
-        b_name.begin(), b_name.end(), cmpChars);
+static bool cmpElemByName(const DrvInfo& a, const DrvInfo& b) {
+  auto a_name = a.queryName();
+  auto b_name = b.queryName();
+  return lexicographical_compare(a_name.begin(), a_name.end(), b_name.begin(),
+                                 b_name.end(), cmpChars);
 }
 
-
 typedef list<Strings> Table;
 
-
-void printTable(Table & table)
-{
-    auto nrColumns = table.size() > 0 ? table.front().size() : 0;
-
-    vector<size_t> widths;
-    widths.resize(nrColumns);
-
-    for (auto & i : table) {
-        assert(i.size() == nrColumns);
-        Strings::iterator j;
-        size_t 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) {
-        Strings::iterator j;
-        size_t column;
-        for (j = i.begin(), column = 0; j != i.end(); ++j, ++column) {
-            string s = *j;
-            replace(s.begin(), s.end(), '\n', ' ');
-            cout << s;
-            if (column < nrColumns - 1)
-                cout << string(widths[column] - s.size() + 2, ' ');
-        }
-        cout << std::endl;
+void printTable(Table& table) {
+  auto nrColumns = table.size() > 0 ? table.front().size() : 0;
+
+  vector<size_t> widths;
+  widths.resize(nrColumns);
+
+  for (auto& i : table) {
+    assert(i.size() == nrColumns);
+    Strings::iterator j;
+    size_t 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) {
+    Strings::iterator j;
+    size_t column;
+    for (j = i.begin(), column = 0; j != i.end(); ++j, ++column) {
+      string s = *j;
+      replace(s.begin(), s.end(), '\n', ' ');
+      cout << s;
+      if (column < nrColumns - 1)
+        cout << string(widths[column] - s.size() + 2, ' ');
     }
+    cout << std::endl;
+  }
 }
 
-
 /* This function compares the version of an element against the
    versions in the given set of elements.  `cvLess' means that only
    lower versions are in the set, `cvEqual' means that at most an
@@ -816,642 +753,647 @@ void printTable(Table & table)
 
 typedef enum { cvLess, cvEqual, cvGreater, cvUnavail } VersionDiff;
 
-static VersionDiff compareVersionAgainstSet(
-    const DrvInfo & elem, const DrvInfos & elems, string & version)
-{
-    DrvName name(elem.queryName());
-
-    VersionDiff diff = cvUnavail;
-    version = "?";
-
-    for (auto & i : elems) {
-        DrvName name2(i.queryName());
-        if (name.name == name2.name) {
-            int d = compareVersions(name.version, name2.version);
-            if (d < 0) {
-                diff = cvGreater;
-                version = name2.version;
-            }
-            else if (diff != cvGreater && d == 0) {
-                diff = cvEqual;
-                version = name2.version;
-            }
-            else if (diff != cvGreater && diff != cvEqual && d > 0) {
-                diff = cvLess;
-                if (version == "" || compareVersions(version, name2.version) < 0)
-                    version = name2.version;
-            }
-        }
+static VersionDiff compareVersionAgainstSet(const DrvInfo& elem,
+                                            const DrvInfos& elems,
+                                            string& version) {
+  DrvName name(elem.queryName());
+
+  VersionDiff diff = cvUnavail;
+  version = "?";
+
+  for (auto& i : elems) {
+    DrvName name2(i.queryName());
+    if (name.name == name2.name) {
+      int d = compareVersions(name.version, name2.version);
+      if (d < 0) {
+        diff = cvGreater;
+        version = name2.version;
+      } else if (diff != cvGreater && d == 0) {
+        diff = cvEqual;
+        version = name2.version;
+      } else if (diff != cvGreater && diff != cvEqual && d > 0) {
+        diff = cvLess;
+        if (version == "" || compareVersions(version, name2.version) < 0)
+          version = name2.version;
+      }
     }
+  }
 
-    return diff;
+  return diff;
 }
 
-
-static void queryJSON(Globals & globals, vector<DrvInfo> & elems)
-{
-    JSONObject topObj(cout, true);
-    for (auto & i : elems) {
-        JSONObject pkgObj = topObj.object(i.attrPath);
-
-        auto drvName = DrvName(i.queryName());
-        pkgObj.attr("name", drvName.fullName);
-        pkgObj.attr("pname", drvName.name);
-        pkgObj.attr("version", drvName.version);
-        pkgObj.attr("system", i.querySystem());
-
-        JSONObject metaObj = pkgObj.object("meta");
-        StringSet metaNames = i.queryMetaNames();
-        for (auto & j : metaNames) {
-            auto placeholder = metaObj.placeholder(j);
-            Value * v = i.queryMeta(j);
-            if (!v) {
-                printError("derivation '%s' has invalid meta attribute '%s'", i.queryName(), j);
-                placeholder.write(nullptr);
-            } else {
-                PathSet context;
-                printValueAsJSON(*globals.state, true, *v, placeholder, context);
-            }
-        }
+static void queryJSON(Globals& globals, vector<DrvInfo>& elems) {
+  JSONObject topObj(cout, true);
+  for (auto& i : elems) {
+    JSONObject pkgObj = topObj.object(i.attrPath);
+
+    auto drvName = DrvName(i.queryName());
+    pkgObj.attr("name", drvName.fullName);
+    pkgObj.attr("pname", drvName.name);
+    pkgObj.attr("version", drvName.version);
+    pkgObj.attr("system", i.querySystem());
+
+    JSONObject metaObj = pkgObj.object("meta");
+    StringSet metaNames = i.queryMetaNames();
+    for (auto& j : metaNames) {
+      auto placeholder = metaObj.placeholder(j);
+      Value* v = i.queryMeta(j);
+      if (!v) {
+        printError("derivation '%s' has invalid meta attribute '%s'",
+                   i.queryName(), j);
+        placeholder.write(nullptr);
+      } else {
+        PathSet context;
+        printValueAsJSON(*globals.state, true, *v, placeholder, context);
+      }
     }
+  }
 }
 
+static void opQuery(Globals& globals, Strings opFlags, Strings opArgs) {
+  Strings remaining;
+  string attrPath;
+
+  bool printStatus = false;
+  bool printName = true;
+  bool printAttrPath = false;
+  bool printSystem = false;
+  bool printDrvPath = false;
+  bool printOutPath = false;
+  bool printDescription = false;
+  bool printMeta = false;
+  bool compareVersions = false;
+  bool xmlOutput = false;
+  bool jsonOutput = false;
+
+  enum { sInstalled, sAvailable } source = sInstalled;
+
+  settings.readOnlyMode = true; /* makes evaluation a bit faster */
+
+  for (Strings::iterator i = opFlags.begin(); i != opFlags.end();) {
+    string arg = *i++;
+    if (arg == "--status" || arg == "-s")
+      printStatus = true;
+    else if (arg == "--no-name")
+      printName = false;
+    else if (arg == "--system")
+      printSystem = true;
+    else if (arg == "--description")
+      printDescription = true;
+    else if (arg == "--compare-versions" || arg == "-c")
+      compareVersions = true;
+    else if (arg == "--drv-path")
+      printDrvPath = true;
+    else if (arg == "--out-path")
+      printOutPath = true;
+    else if (arg == "--meta")
+      printMeta = true;
+    else if (arg == "--installed")
+      source = sInstalled;
+    else if (arg == "--available" || arg == "-a")
+      source = sAvailable;
+    else if (arg == "--xml")
+      xmlOutput = true;
+    else if (arg == "--json")
+      jsonOutput = true;
+    else if (arg == "--attr-path" || arg == "-P")
+      printAttrPath = true;
+    else if (arg == "--attr" || arg == "-A")
+      attrPath = needArg(i, opFlags, arg);
+    else
+      throw UsageError(format("unknown flag '%1%'") % arg);
+  }
+
+  /* Obtain derivation information from the specified source. */
+  DrvInfos availElems, installedElems;
+
+  if (source == sInstalled || compareVersions || printStatus)
+    installedElems = queryInstalled(*globals.state, globals.profile);
+
+  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,
+      opArgs, false);
+
+  DrvInfos& otherElems(source == sInstalled ? availElems : installedElems);
+
+  /* Sort them by name. */
+  /* !!! */
+  vector<DrvInfo> elems;
+  for (auto& i : elems_) elems.push_back(i);
+  sort(elems.begin(), elems.end(), cmpElemByName);
+
+  /* We only need to know the installed paths when we are querying
+     the status of the derivation. */
+  PathSet installed; /* installed paths */
+
+  if (printStatus) {
+    for (auto& i : installedElems) installed.insert(i.queryOutPath());
+  }
+
+  /* Query which paths have substitutes. */
+  PathSet validPaths, substitutablePaths;
+  if (printStatus || globals.prebuiltOnly) {
+    PathSet paths;
+    for (auto& i : elems) try {
+        paths.insert(i.queryOutPath());
+      } catch (AssertionError& e) {
+        printMsg(
+            lvlTalkative,
+            "skipping derivation named '%s' which gives an assertion failure",
+            i.queryName());
+        i.setFailed();
+      }
+    validPaths = globals.state->store->queryValidPaths(paths);
+    substitutablePaths = globals.state->store->querySubstitutablePaths(paths);
+  }
+
+  /* Print the desired columns, or XML output. */
+  if (jsonOutput) {
+    queryJSON(globals, elems);
+    return;
+  }
+
+  bool tty = isatty(STDOUT_FILENO);
+  RunPager pager;
+
+  Table table;
+  std::ostringstream dummy;
+  XMLWriter xml(true, *(xmlOutput ? &cout : &dummy));
+  XMLOpenElement xmlRoot(xml, "items");
+
+  for (auto& i : elems) {
+    try {
+      if (i.hasFailed()) continue;
+
+      // Activity act(*logger, lvlDebug, format("outputting query result '%1%'")
+      // % i.attrPath);
+
+      if (globals.prebuiltOnly &&
+          validPaths.find(i.queryOutPath()) == validPaths.end() &&
+          substitutablePaths.find(i.queryOutPath()) == substitutablePaths.end())
+        continue;
+
+      /* For table output. */
+      Strings columns;
+
+      /* For XML output. */
+      XMLAttrs attrs;
+
+      if (printStatus) {
+        Path outPath = i.queryOutPath();
+        bool hasSubs =
+            substitutablePaths.find(outPath) != substitutablePaths.end();
+        bool isInstalled = installed.find(outPath) != installed.end();
+        bool isValid = validPaths.find(outPath) != validPaths.end();
+        if (xmlOutput) {
+          attrs["installed"] = isInstalled ? "1" : "0";
+          attrs["valid"] = isValid ? "1" : "0";
+          attrs["substitutable"] = hasSubs ? "1" : "0";
+        } else
+          columns.push_back((string)(isInstalled ? "I" : "-") +
+                            (isValid ? "P" : "-") + (hasSubs ? "S" : "-"));
+      }
+
+      if (xmlOutput)
+        attrs["attrPath"] = i.attrPath;
+      else if (printAttrPath)
+        columns.push_back(i.attrPath);
+
+      if (xmlOutput) {
+        auto drvName = DrvName(i.queryName());
+        attrs["name"] = drvName.fullName;
+        attrs["pname"] = drvName.name;
+        attrs["version"] = drvName.version;
+      } else if (printName) {
+        columns.push_back(i.queryName());
+      }
+
+      if (compareVersions) {
+        /* Compare this element against the versions of the
+           same named packages in either the set of available
+           elements, or the set of installed elements.  !!!
+           This is O(N * M), should be O(N * lg M). */
+        string version;
+        VersionDiff diff = compareVersionAgainstSet(i, otherElems, version);
+
+        char ch;
+        switch (diff) {
+          case cvLess:
+            ch = '>';
+            break;
+          case cvEqual:
+            ch = '=';
+            break;
+          case cvGreater:
+            ch = '<';
+            break;
+          case cvUnavail:
+            ch = '-';
+            break;
+          default:
+            abort();
+        }
 
-static void opQuery(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    Strings remaining;
-    string attrPath;
-
-    bool printStatus = false;
-    bool printName = true;
-    bool printAttrPath = false;
-    bool printSystem = false;
-    bool printDrvPath = false;
-    bool printOutPath = false;
-    bool printDescription = false;
-    bool printMeta = false;
-    bool compareVersions = false;
-    bool xmlOutput = false;
-    bool jsonOutput = false;
-
-    enum { sInstalled, sAvailable } source = sInstalled;
-
-    settings.readOnlyMode = true; /* makes evaluation a bit faster */
-
-    for (Strings::iterator i = opFlags.begin(); i != opFlags.end(); ) {
-        string arg = *i++;
-        if (arg == "--status" || arg == "-s") printStatus = true;
-        else if (arg == "--no-name") printName = false;
-        else if (arg == "--system") printSystem = true;
-        else if (arg == "--description") printDescription = true;
-        else if (arg == "--compare-versions" || arg == "-c") compareVersions = true;
-        else if (arg == "--drv-path") printDrvPath = true;
-        else if (arg == "--out-path") printOutPath = true;
-        else if (arg == "--meta") printMeta = true;
-        else if (arg == "--installed") source = sInstalled;
-        else if (arg == "--available" || arg == "-a") source = sAvailable;
-        else if (arg == "--xml") xmlOutput = true;
-        else if (arg == "--json") jsonOutput = true;
-        else if (arg == "--attr-path" || arg == "-P") printAttrPath = true;
-        else if (arg == "--attr" || arg == "-A")
-            attrPath = needArg(i, opFlags, arg);
-        else
-            throw UsageError(format("unknown flag '%1%'") % arg);
-    }
-
-
-    /* Obtain derivation information from the specified source. */
-    DrvInfos availElems, installedElems;
-
-    if (source == sInstalled || compareVersions || printStatus)
-        installedElems = queryInstalled(*globals.state, globals.profile);
-
-    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,
-        opArgs, false);
-
-    DrvInfos & otherElems(source == sInstalled ? availElems : installedElems);
-
-
-    /* Sort them by name. */
-    /* !!! */
-    vector<DrvInfo> elems;
-    for (auto & i : elems_) elems.push_back(i);
-    sort(elems.begin(), elems.end(), cmpElemByName);
-
-
-    /* We only need to know the installed paths when we are querying
-       the status of the derivation. */
-    PathSet installed; /* installed paths */
-
-    if (printStatus) {
-        for (auto & i : installedElems)
-            installed.insert(i.queryOutPath());
-    }
-
-
-    /* Query which paths have substitutes. */
-    PathSet validPaths, substitutablePaths;
-    if (printStatus || globals.prebuiltOnly) {
-        PathSet paths;
-        for (auto & i : elems)
-            try {
-                paths.insert(i.queryOutPath());
-            } catch (AssertionError & e) {
-                printMsg(lvlTalkative, "skipping derivation named '%s' which gives an assertion failure", i.queryName());
-                i.setFailed();
-            }
-        validPaths = globals.state->store->queryValidPaths(paths);
-        substitutablePaths = globals.state->store->querySubstitutablePaths(paths);
-    }
-
-
-    /* Print the desired columns, or XML output. */
-    if (jsonOutput) {
-        queryJSON(globals, elems);
-        return;
-    }
-
-    bool tty = isatty(STDOUT_FILENO);
-    RunPager pager;
-
-    Table table;
-    std::ostringstream dummy;
-    XMLWriter xml(true, *(xmlOutput ? &cout : &dummy));
-    XMLOpenElement xmlRoot(xml, "items");
-
-    for (auto & i : elems) {
-        try {
-            if (i.hasFailed()) continue;
-
-            //Activity act(*logger, lvlDebug, format("outputting query result '%1%'") % i.attrPath);
-
-            if (globals.prebuiltOnly &&
-                validPaths.find(i.queryOutPath()) == validPaths.end() &&
-                substitutablePaths.find(i.queryOutPath()) == substitutablePaths.end())
-                continue;
-
-            /* For table output. */
-            Strings columns;
-
-            /* For XML output. */
-            XMLAttrs attrs;
-
-            if (printStatus) {
-                Path outPath = i.queryOutPath();
-                bool hasSubs = substitutablePaths.find(outPath) != substitutablePaths.end();
-                bool isInstalled = installed.find(outPath) != installed.end();
-                bool isValid = validPaths.find(outPath) != validPaths.end();
-                if (xmlOutput) {
-                    attrs["installed"] = isInstalled ? "1" : "0";
-                    attrs["valid"] = isValid ? "1" : "0";
-                    attrs["substitutable"] = hasSubs ? "1" : "0";
-                } else
-                    columns.push_back(
-                        (string) (isInstalled ? "I" : "-")
-                        + (isValid ? "P" : "-")
-                        + (hasSubs ? "S" : "-"));
-            }
-
-            if (xmlOutput)
-                attrs["attrPath"] = i.attrPath;
-            else if (printAttrPath)
-                columns.push_back(i.attrPath);
-
-            if (xmlOutput) {
-                auto drvName = DrvName(i.queryName());
-                attrs["name"] = drvName.fullName;
-                attrs["pname"] = drvName.name;
-                attrs["version"] = drvName.version;
-            } else if (printName) {
-                columns.push_back(i.queryName());
-            }
-
-            if (compareVersions) {
-                /* Compare this element against the versions of the
-                   same named packages in either the set of available
-                   elements, or the set of installed elements.  !!!
-                   This is O(N * M), should be O(N * lg M). */
-                string version;
-                VersionDiff diff = compareVersionAgainstSet(i, otherElems, version);
-
-                char ch;
-                switch (diff) {
-                    case cvLess: ch = '>'; break;
-                    case cvEqual: ch = '='; break;
-                    case cvGreater: ch = '<'; break;
-                    case cvUnavail: ch = '-'; break;
-                    default: abort();
-                }
-
-                if (xmlOutput) {
-                    if (diff != cvUnavail) {
-                        attrs["versionDiff"] = ch;
-                        attrs["maxComparedVersion"] = version;
-                    }
-                } else {
-                    string column = (string) "" + ch + " " + version;
-                    if (diff == cvGreater && tty)
-                        column = ANSI_RED + column + ANSI_NORMAL;
-                    columns.push_back(column);
-                }
-            }
-
-            if (xmlOutput) {
-                if (i.querySystem() != "") attrs["system"] = i.querySystem();
-            }
-            else if (printSystem)
-                columns.push_back(i.querySystem());
-
-            if (printDrvPath) {
-                string drvPath = i.queryDrvPath();
-                if (xmlOutput) {
-                    if (drvPath != "") attrs["drvPath"] = drvPath;
-                } else
-                    columns.push_back(drvPath == "" ? "-" : drvPath);
+        if (xmlOutput) {
+          if (diff != cvUnavail) {
+            attrs["versionDiff"] = ch;
+            attrs["maxComparedVersion"] = version;
+          }
+        } else {
+          string column = (string) "" + ch + " " + version;
+          if (diff == cvGreater && tty)
+            column = ANSI_RED + column + ANSI_NORMAL;
+          columns.push_back(column);
+        }
+      }
+
+      if (xmlOutput) {
+        if (i.querySystem() != "") attrs["system"] = i.querySystem();
+      } else if (printSystem)
+        columns.push_back(i.querySystem());
+
+      if (printDrvPath) {
+        string drvPath = i.queryDrvPath();
+        if (xmlOutput) {
+          if (drvPath != "") attrs["drvPath"] = drvPath;
+        } else
+          columns.push_back(drvPath == "" ? "-" : drvPath);
+      }
+
+      if (printOutPath && !xmlOutput) {
+        DrvInfo::Outputs outputs = i.queryOutputs();
+        string s;
+        for (auto& j : outputs) {
+          if (!s.empty()) s += ';';
+          if (j.first != "out") {
+            s += j.first;
+            s += "=";
+          }
+          s += j.second;
+        }
+        columns.push_back(s);
+      }
+
+      if (printDescription) {
+        string descr = i.queryMetaString("description");
+        if (xmlOutput) {
+          if (descr != "") attrs["description"] = descr;
+        } else
+          columns.push_back(descr);
+      }
+
+      if (xmlOutput) {
+        if (printOutPath || printMeta) {
+          XMLOpenElement item(xml, "item", attrs);
+          if (printOutPath) {
+            DrvInfo::Outputs outputs = i.queryOutputs();
+            for (auto& j : outputs) {
+              XMLAttrs attrs2;
+              attrs2["name"] = j.first;
+              attrs2["path"] = j.second;
+              xml.writeEmptyElement("output", attrs2);
             }
-
-            if (printOutPath && !xmlOutput) {
-                DrvInfo::Outputs outputs = i.queryOutputs();
-                string s;
-                for (auto & j : outputs) {
-                    if (!s.empty()) s += ';';
-                    if (j.first != "out") { s += j.first; s += "="; }
-                    s += j.second;
+          }
+          if (printMeta) {
+            StringSet metaNames = i.queryMetaNames();
+            for (auto& j : metaNames) {
+              XMLAttrs attrs2;
+              attrs2["name"] = j;
+              Value* v = i.queryMeta(j);
+              if (!v)
+                printError("derivation '%s' has invalid meta attribute '%s'",
+                           i.queryName(), j);
+              else {
+                if (v->type == tString) {
+                  attrs2["type"] = "string";
+                  attrs2["value"] = v->string.s;
+                  xml.writeEmptyElement("meta", attrs2);
+                } else if (v->type == tInt) {
+                  attrs2["type"] = "int";
+                  attrs2["value"] = (format("%1%") % v->integer).str();
+                  xml.writeEmptyElement("meta", attrs2);
+                } else if (v->type == tFloat) {
+                  attrs2["type"] = "float";
+                  attrs2["value"] = (format("%1%") % v->fpoint).str();
+                  xml.writeEmptyElement("meta", attrs2);
+                } else if (v->type == tBool) {
+                  attrs2["type"] = "bool";
+                  attrs2["value"] = v->boolean ? "true" : "false";
+                  xml.writeEmptyElement("meta", attrs2);
+                } else if (v->isList()) {
+                  attrs2["type"] = "strings";
+                  XMLOpenElement m(xml, "meta", attrs2);
+                  for (unsigned int j = 0; j < v->listSize(); ++j) {
+                    if (v->listElems()[j]->type != tString) continue;
+                    XMLAttrs attrs3;
+                    attrs3["value"] = v->listElems()[j]->string.s;
+                    xml.writeEmptyElement("string", attrs3);
+                  }
+                } else if (v->type == tAttrs) {
+                  attrs2["type"] = "strings";
+                  XMLOpenElement m(xml, "meta", attrs2);
+                  Bindings& attrs = *v->attrs;
+                  for (auto& i : attrs) {
+                    Attr& a(*attrs.find(i.name));
+                    if (a.value->type != tString) continue;
+                    XMLAttrs attrs3;
+                    attrs3["type"] = i.name;
+                    attrs3["value"] = a.value->string.s;
+                    xml.writeEmptyElement("string", attrs3);
+                  }
                 }
-                columns.push_back(s);
-            }
-
-            if (printDescription) {
-                string descr = i.queryMetaString("description");
-                if (xmlOutput) {
-                    if (descr != "") attrs["description"] = descr;
-                } else
-                    columns.push_back(descr);
+              }
             }
-
-            if (xmlOutput) {
-                if (printOutPath || printMeta) {
-                    XMLOpenElement item(xml, "item", attrs);
-                    if (printOutPath) {
-                        DrvInfo::Outputs outputs = i.queryOutputs();
-                        for (auto & j : outputs) {
-                            XMLAttrs attrs2;
-                            attrs2["name"] = j.first;
-                            attrs2["path"] = j.second;
-                            xml.writeEmptyElement("output", attrs2);
-                        }
-                    }
-                    if (printMeta) {
-                        StringSet metaNames = i.queryMetaNames();
-                        for (auto & j : metaNames) {
-                            XMLAttrs attrs2;
-                            attrs2["name"] = j;
-                            Value * v = i.queryMeta(j);
-                            if (!v)
-                                printError("derivation '%s' has invalid meta attribute '%s'", i.queryName(), j);
-                            else {
-                                if (v->type == tString) {
-                                    attrs2["type"] = "string";
-                                    attrs2["value"] = v->string.s;
-                                    xml.writeEmptyElement("meta", attrs2);
-                                } else if (v->type == tInt) {
-                                    attrs2["type"] = "int";
-                                    attrs2["value"] = (format("%1%") % v->integer).str();
-                                    xml.writeEmptyElement("meta", attrs2);
-                                } else if (v->type == tFloat) {
-                                    attrs2["type"] = "float";
-                                    attrs2["value"] = (format("%1%") % v->fpoint).str();
-                                    xml.writeEmptyElement("meta", attrs2);
-                                } else if (v->type == tBool) {
-                                    attrs2["type"] = "bool";
-                                    attrs2["value"] = v->boolean ? "true" : "false";
-                                    xml.writeEmptyElement("meta", attrs2);
-                                } else if (v->isList()) {
-                                    attrs2["type"] = "strings";
-                                    XMLOpenElement m(xml, "meta", attrs2);
-                                    for (unsigned int j = 0; j < v->listSize(); ++j) {
-                                        if (v->listElems()[j]->type != tString) continue;
-                                        XMLAttrs attrs3;
-                                        attrs3["value"] = v->listElems()[j]->string.s;
-                                        xml.writeEmptyElement("string", attrs3);
-                                    }
-                              } else if (v->type == tAttrs) {
-                                  attrs2["type"] = "strings";
-                                  XMLOpenElement m(xml, "meta", attrs2);
-                                  Bindings & attrs = *v->attrs;
-                                  for (auto &i : attrs) {
-                                      Attr & a(*attrs.find(i.name));
-                                      if(a.value->type != tString) continue;
-                                      XMLAttrs attrs3;
-                                      attrs3["type"] = i.name;
-                                      attrs3["value"] = a.value->string.s;
-                                      xml.writeEmptyElement("string", attrs3);
-                                }
-                              }
-                            }
-                        }
-                    }
-                } else
-                    xml.writeEmptyElement("item", attrs);
-            } else
-                table.push_back(columns);
-
-            cout.flush();
-
-        } catch (AssertionError & e) {
-            printMsg(lvlTalkative, "skipping derivation named '%1%' which gives an assertion failure", i.queryName());
-        } catch (Error & e) {
-            e.addPrefix(fmt("while querying the derivation named '%1%':\n", i.queryName()));
-            throw;
-        }
+          }
+        } else
+          xml.writeEmptyElement("item", attrs);
+      } else
+        table.push_back(columns);
+
+      cout.flush();
+
+    } catch (AssertionError& e) {
+      printMsg(
+          lvlTalkative,
+          "skipping derivation named '%1%' which gives an assertion failure",
+          i.queryName());
+    } catch (Error& e) {
+      e.addPrefix(
+          fmt("while querying the derivation named '%1%':\n", i.queryName()));
+      throw;
     }
+  }
 
-    if (!xmlOutput) printTable(table);
+  if (!xmlOutput) printTable(table);
 }
 
+static void opSwitchProfile(Globals& globals, Strings opFlags, Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  if (opArgs.size() != 1)
+    throw UsageError(format("exactly one argument expected"));
 
-static void opSwitchProfile(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    if (opArgs.size() != 1)
-        throw UsageError(format("exactly one argument expected"));
-
-    Path profile = absPath(opArgs.front());
-    Path profileLink = getHome() + "/.nix-profile";
+  Path profile = absPath(opArgs.front());
+  Path profileLink = getHome() + "/.nix-profile";
 
-    switchLink(profileLink, profile);
+  switchLink(profileLink, profile);
 }
 
-
 static const int prevGen = -2;
 
+static void switchGeneration(Globals& globals, int dstGen) {
+  PathLocks lock;
+  lockProfile(lock, globals.profile);
 
-static void switchGeneration(Globals & globals, int dstGen)
-{
-    PathLocks lock;
-    lockProfile(lock, globals.profile);
-
-    int curGen;
-    Generations gens = findGenerations(globals.profile, curGen);
+  int curGen;
+  Generations gens = findGenerations(globals.profile, curGen);
 
-    Generation dst;
-    for (auto & i : gens)
-        if ((dstGen == prevGen && i.number < curGen) ||
-            (dstGen >= 0 && i.number == dstGen))
-            dst = i;
+  Generation dst;
+  for (auto& i : gens)
+    if ((dstGen == prevGen && i.number < curGen) ||
+        (dstGen >= 0 && i.number == dstGen))
+      dst = i;
 
-    if (!dst) {
-        if (dstGen == prevGen)
-            throw Error(format("no generation older than the current (%1%) exists")
-                % curGen);
-        else
-            throw Error(format("generation %1% does not exist") % dstGen);
-    }
+  if (!dst) {
+    if (dstGen == prevGen)
+      throw Error(format("no generation older than the current (%1%) exists") %
+                  curGen);
+    else
+      throw Error(format("generation %1% does not exist") % dstGen);
+  }
 
-    printInfo(format("switching from generation %1% to %2%")
-        % curGen % dst.number);
+  printInfo(format("switching from generation %1% to %2%") % curGen %
+            dst.number);
 
-    if (globals.dryRun) return;
+  if (globals.dryRun) return;
 
-    switchLink(globals.profile, dst.path);
+  switchLink(globals.profile, dst.path);
 }
 
+static void opSwitchGeneration(Globals& globals, Strings opFlags,
+                               Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  if (opArgs.size() != 1)
+    throw UsageError(format("exactly one argument expected"));
 
-static void opSwitchGeneration(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    if (opArgs.size() != 1)
-        throw UsageError(format("exactly one argument expected"));
+  int dstGen;
+  if (!string2Int(opArgs.front(), dstGen))
+    throw UsageError(format("expected a generation number"));
 
-    int dstGen;
-    if (!string2Int(opArgs.front(), dstGen))
-        throw UsageError(format("expected a generation number"));
-
-    switchGeneration(globals, dstGen);
+  switchGeneration(globals, dstGen);
 }
 
+static void opRollback(Globals& globals, Strings opFlags, Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  if (opArgs.size() != 0) throw UsageError(format("no arguments expected"));
 
-static void opRollback(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    if (opArgs.size() != 0)
-        throw UsageError(format("no arguments expected"));
-
-    switchGeneration(globals, prevGen);
+  switchGeneration(globals, prevGen);
 }
 
+static void opListGenerations(Globals& globals, Strings opFlags,
+                              Strings opArgs) {
+  if (opFlags.size() > 0)
+    throw UsageError(format("unknown flag '%1%'") % opFlags.front());
+  if (opArgs.size() != 0) throw UsageError(format("no arguments expected"));
 
-static void opListGenerations(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    if (opFlags.size() > 0)
-        throw UsageError(format("unknown flag '%1%'") % opFlags.front());
-    if (opArgs.size() != 0)
-        throw UsageError(format("no arguments expected"));
+  PathLocks lock;
+  lockProfile(lock, globals.profile);
 
-    PathLocks lock;
-    lockProfile(lock, globals.profile);
+  int curGen;
+  Generations gens = findGenerations(globals.profile, curGen);
 
-    int curGen;
-    Generations gens = findGenerations(globals.profile, curGen);
+  RunPager pager;
 
-    RunPager pager;
-
-    for (auto & i : gens) {
-        tm t;
-        if (!localtime_r(&i.creationTime, &t)) throw Error("cannot convert time");
-        cout << format("%|4|   %|4|-%|02|-%|02| %|02|:%|02|:%|02|   %||\n")
-            % i.number
-            % (t.tm_year + 1900) % (t.tm_mon + 1) % t.tm_mday
-            % t.tm_hour % t.tm_min % t.tm_sec
-            % (i.number == curGen ? "(current)" : "");
-    }
+  for (auto& i : gens) {
+    tm t;
+    if (!localtime_r(&i.creationTime, &t)) throw Error("cannot convert time");
+    cout << format("%|4|   %|4|-%|02|-%|02| %|02|:%|02|:%|02|   %||\n") %
+                i.number % (t.tm_year + 1900) % (t.tm_mon + 1) % t.tm_mday %
+                t.tm_hour % t.tm_min % t.tm_sec %
+                (i.number == curGen ? "(current)" : "");
+  }
 }
 
-
-static void opDeleteGenerations(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    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)
-            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)
-            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))
-                throw UsageError(format("invalid generation number '%1%'") % i);
-            gens.insert(n);
-        }
-        deleteGenerations(globals.profile, gens, globals.dryRun);
+static void opDeleteGenerations(Globals& globals, Strings opFlags,
+                                Strings opArgs) {
+  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)
+      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)
+      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))
+        throw UsageError(format("invalid generation number '%1%'") % i);
+      gens.insert(n);
     }
+    deleteGenerations(globals.profile, gens, globals.dryRun);
+  }
 }
 
-
-static void opVersion(Globals & globals, Strings opFlags, Strings opArgs)
-{
-    printVersion("nix-env");
+static void opVersion(Globals& globals, Strings opFlags, Strings opArgs) {
+  printVersion("nix-env");
 }
 
+static int _main(int argc, char** argv) {
+  {
+    Strings opFlags, opArgs;
+    Operation op = 0;
+    RepairFlag repair = NoRepair;
+    string file;
+
+    Globals globals;
+
+    globals.instSource.type = srcUnknown;
+    globals.instSource.nixExprPath = getHome() + "/.nix-defexpr";
+    globals.instSource.systemFilter = "*";
+
+    if (!pathExists(globals.instSource.nixExprPath)) {
+      try {
+        createDirs(globals.instSource.nixExprPath);
+        replaceSymlink(fmt("%s/profiles/per-user/%s/channels",
+                           settings.nixStateDir, getUserName()),
+                       globals.instSource.nixExprPath + "/channels");
+        if (getuid() != 0)
+          replaceSymlink(
+              fmt("%s/profiles/per-user/root/channels", settings.nixStateDir),
+              globals.instSource.nixExprPath + "/channels_root");
+      } catch (Error&) {
+      }
+    }
 
-static int _main(int argc, char * * argv)
-{
-    {
-        Strings opFlags, opArgs;
-        Operation op = 0;
-        RepairFlag repair = NoRepair;
-        string file;
-
-        Globals globals;
-
-        globals.instSource.type = srcUnknown;
-        globals.instSource.nixExprPath = getHome() + "/.nix-defexpr";
-        globals.instSource.systemFilter = "*";
-
-        if (!pathExists(globals.instSource.nixExprPath)) {
-            try {
-                createDirs(globals.instSource.nixExprPath);
-                replaceSymlink(
-                    fmt("%s/profiles/per-user/%s/channels", settings.nixStateDir, getUserName()),
-                    globals.instSource.nixExprPath + "/channels");
-                if (getuid() != 0)
-                    replaceSymlink(
-                        fmt("%s/profiles/per-user/root/channels", settings.nixStateDir),
-                        globals.instSource.nixExprPath + "/channels_root");
-            } catch (Error &) { }
-        }
-
-        globals.dryRun = false;
-        globals.preserveInstalled = false;
-        globals.removeAll = false;
-        globals.prebuiltOnly = false;
-
-        struct MyArgs : LegacyArgs, MixEvalArgs
-        {
-            using LegacyArgs::LegacyArgs;
-        };
-
-        MyArgs myArgs(baseNameOf(argv[0]), [&](Strings::iterator & arg, const Strings::iterator & end) {
-            Operation oldOp = op;
-
-            if (*arg == "--help")
-                showManPage("nix-env");
-            else if (*arg == "--version")
-                op = opVersion;
-            else if (*arg == "--install" || *arg == "-i")
-                op = opInstall;
-            else if (*arg == "--force-name") // undocumented flag for nix-install-package
-                globals.forceName = getArg(*arg, arg, end);
-            else if (*arg == "--uninstall" || *arg == "-e")
-                op = opUninstall;
-            else if (*arg == "--upgrade" || *arg == "-u")
-                op = opUpgrade;
-            else if (*arg == "--set-flag")
-                op = opSetFlag;
-            else if (*arg == "--set")
-                op = opSet;
-            else if (*arg == "--query" || *arg == "-q")
-                op = opQuery;
-            else if (*arg == "--profile" || *arg == "-p")
-                globals.profile = absPath(getArg(*arg, arg, end));
-            else if (*arg == "--file" || *arg == "-f")
-                file = getArg(*arg, arg, end);
-            else if (*arg == "--switch-profile" || *arg == "-S")
-                op = opSwitchProfile;
-            else if (*arg == "--switch-generation" || *arg == "-G")
-                op = opSwitchGeneration;
-            else if (*arg == "--rollback")
-                op = opRollback;
-            else if (*arg == "--list-generations")
-                op = opListGenerations;
-            else if (*arg == "--delete-generations")
-                op = opDeleteGenerations;
-            else if (*arg == "--dry-run") {
-                printInfo("(dry run; not doing anything)");
-                globals.dryRun = true;
-            }
-            else if (*arg == "--system-filter")
-                globals.instSource.systemFilter = getArg(*arg, arg, end);
-            else if (*arg == "--prebuilt-only" || *arg == "-b")
-                globals.prebuiltOnly = true;
-            else if (*arg == "--repair")
-                repair = Repair;
-            else if (*arg != "" && arg->at(0) == '-') {
-                opFlags.push_back(*arg);
-                /* FIXME: hacky */
-                if (*arg == "--from-profile" ||
-                    (op == opQuery && (*arg == "--attr" || *arg == "-A")))
-                    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;
-        });
-
-        myArgs.parseCmdline(argvToStrings(argc, argv));
-
-        initPlugins();
-
-        if (!op) throw UsageError("no operation specified");
-
-        auto store = openStore();
-
-        globals.state = std::shared_ptr<EvalState>(new EvalState(myArgs.searchPath, store));
-        globals.state->repair = repair;
-
-        if (file != "")
-            globals.instSource.nixExprPath = lookupFileArg(*globals.state, file);
-
-        globals.instSource.autoArgs = myArgs.getAutoArgs(*globals.state);
-
-        if (globals.profile == "")
-            globals.profile = getEnv("NIX_PROFILE", "");
-
-        if (globals.profile == "") {
-            Path profileLink = getHome() + "/.nix-profile";
-            try {
-                if (!pathExists(profileLink)) {
-                    replaceSymlink(
-                        getuid() == 0
-                        ? settings.nixStateDir + "/profiles/default"
-                        : fmt("%s/profiles/per-user/%s/profile", settings.nixStateDir, getUserName()),
-                        profileLink);
-                }
-                globals.profile = absPath(readLink(profileLink), dirOf(profileLink));
-            } catch (Error &) {
-                globals.profile = profileLink;
-            }
+    globals.dryRun = false;
+    globals.preserveInstalled = false;
+    globals.removeAll = false;
+    globals.prebuiltOnly = false;
+
+    struct MyArgs : LegacyArgs, MixEvalArgs {
+      using LegacyArgs::LegacyArgs;
+    };
+
+    MyArgs myArgs(baseNameOf(argv[0]), [&](Strings::iterator& arg,
+                                           const Strings::iterator& end) {
+      Operation oldOp = op;
+
+      if (*arg == "--help")
+        showManPage("nix-env");
+      else if (*arg == "--version")
+        op = opVersion;
+      else if (*arg == "--install" || *arg == "-i")
+        op = opInstall;
+      else if (*arg ==
+               "--force-name")  // undocumented flag for nix-install-package
+        globals.forceName = getArg(*arg, arg, end);
+      else if (*arg == "--uninstall" || *arg == "-e")
+        op = opUninstall;
+      else if (*arg == "--upgrade" || *arg == "-u")
+        op = opUpgrade;
+      else if (*arg == "--set-flag")
+        op = opSetFlag;
+      else if (*arg == "--set")
+        op = opSet;
+      else if (*arg == "--query" || *arg == "-q")
+        op = opQuery;
+      else if (*arg == "--profile" || *arg == "-p")
+        globals.profile = absPath(getArg(*arg, arg, end));
+      else if (*arg == "--file" || *arg == "-f")
+        file = getArg(*arg, arg, end);
+      else if (*arg == "--switch-profile" || *arg == "-S")
+        op = opSwitchProfile;
+      else if (*arg == "--switch-generation" || *arg == "-G")
+        op = opSwitchGeneration;
+      else if (*arg == "--rollback")
+        op = opRollback;
+      else if (*arg == "--list-generations")
+        op = opListGenerations;
+      else if (*arg == "--delete-generations")
+        op = opDeleteGenerations;
+      else if (*arg == "--dry-run") {
+        printInfo("(dry run; not doing anything)");
+        globals.dryRun = true;
+      } else if (*arg == "--system-filter")
+        globals.instSource.systemFilter = getArg(*arg, arg, end);
+      else if (*arg == "--prebuilt-only" || *arg == "-b")
+        globals.prebuiltOnly = true;
+      else if (*arg == "--repair")
+        repair = Repair;
+      else if (*arg != "" && arg->at(0) == '-') {
+        opFlags.push_back(*arg);
+        /* FIXME: hacky */
+        if (*arg == "--from-profile" ||
+            (op == opQuery && (*arg == "--attr" || *arg == "-A")))
+          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;
+    });
+
+    myArgs.parseCmdline(argvToStrings(argc, argv));
+
+    initPlugins();
+
+    if (!op) throw UsageError("no operation specified");
+
+    auto store = openStore();
+
+    globals.state =
+        std::shared_ptr<EvalState>(new EvalState(myArgs.searchPath, store));
+    globals.state->repair = repair;
+
+    if (file != "")
+      globals.instSource.nixExprPath = lookupFileArg(*globals.state, file);
+
+    globals.instSource.autoArgs = myArgs.getAutoArgs(*globals.state);
+
+    if (globals.profile == "") globals.profile = getEnv("NIX_PROFILE", "");
+
+    if (globals.profile == "") {
+      Path profileLink = getHome() + "/.nix-profile";
+      try {
+        if (!pathExists(profileLink)) {
+          replaceSymlink(getuid() == 0
+                             ? settings.nixStateDir + "/profiles/default"
+                             : fmt("%s/profiles/per-user/%s/profile",
+                                   settings.nixStateDir, getUserName()),
+                         profileLink);
         }
+        globals.profile = absPath(readLink(profileLink), dirOf(profileLink));
+      } catch (Error&) {
+        globals.profile = profileLink;
+      }
+    }
 
-        op(globals, opFlags, opArgs);
+    op(globals, opFlags, opArgs);
 
-        globals.state->printStats();
+    globals.state->printStats();
 
-        return 0;
-    }
+    return 0;
+  }
 }
 
 static RegisterLegacyCommand s1("nix-env", _main);
diff --git a/third_party/nix/src/nix-env/user-env.cc b/third_party/nix/src/nix-env/user-env.cc
index 7b9a88281171..c1c174bcc529 100644
--- a/third_party/nix/src/nix-env/user-env.cc
+++ b/third_party/nix/src/nix-env/user-env.cc
@@ -1,156 +1,152 @@
 #include "user-env.hh"
-#include "util.hh"
 #include "derivations.hh"
-#include "store-api.hh"
-#include "globals.hh"
-#include "shared.hh"
-#include "eval.hh"
 #include "eval-inline.hh"
+#include "eval.hh"
+#include "globals.hh"
 #include "profiles.hh"
-
+#include "shared.hh"
+#include "store-api.hh"
+#include "util.hh"
 
 namespace nix {
 
-
-DrvInfos queryInstalled(EvalState & state, const Path & userEnv)
-{
-    DrvInfos elems;
-    Path manifestFile = userEnv + "/manifest.nix";
-    if (pathExists(manifestFile)) {
-        Value v;
-        state.evalFile(manifestFile, v);
-        Bindings & bindings(*state.allocBindings(0));
-        getDerivations(state, v, "", bindings, elems, false);
-    }
-    return elems;
+DrvInfos queryInstalled(EvalState& state, const Path& userEnv) {
+  DrvInfos elems;
+  Path manifestFile = userEnv + "/manifest.nix";
+  if (pathExists(manifestFile)) {
+    Value v;
+    state.evalFile(manifestFile, v);
+    Bindings& bindings(*state.allocBindings(0));
+    getDerivations(state, v, "", bindings, elems, false);
+  }
+  return elems;
 }
 
-
-bool createUserEnv(EvalState & state, DrvInfos & elems,
-    const Path & profile, bool keepDerivations,
-    const string & lockToken)
-{
-    /* Build the components in the user environment, if they don't
-       exist already. */
-    PathSet drvsToBuild;
-    for (auto & i : elems)
-        if (i.queryDrvPath() != "")
-            drvsToBuild.insert(i.queryDrvPath());
-
-    debug(format("building user environment dependencies"));
-    state.store->buildPaths(drvsToBuild, state.repair ? bmRepair : bmNormal);
-
-    /* Construct the whole top level derivation. */
-    PathSet references;
-    Value manifest;
-    state.mkList(manifest, elems.size());
-    unsigned int n = 0;
-    for (auto & i : elems) {
-        /* Create a pseudo-derivation containing the name, system,
-           output paths, and optionally the derivation path, as well
-           as the meta attributes. */
-        Path drvPath = keepDerivations ? i.queryDrvPath() : "";
-
-        Value & v(*state.allocValue());
-        manifest.listElems()[n++] = &v;
-        state.mkAttrs(v, 16);
-
-        mkString(*state.allocAttr(v, state.sType), "derivation");
-        mkString(*state.allocAttr(v, state.sName), i.queryName());
-        auto system = i.querySystem();
-        if (!system.empty())
-            mkString(*state.allocAttr(v, state.sSystem), system);
-        mkString(*state.allocAttr(v, state.sOutPath), i.queryOutPath());
-        if (drvPath != "")
-            mkString(*state.allocAttr(v, state.sDrvPath), i.queryDrvPath());
-
-        // Copy each output meant for installation.
-        DrvInfo::Outputs outputs = i.queryOutputs(true);
-        Value & vOutputs = *state.allocAttr(v, state.sOutputs);
-        state.mkList(vOutputs, outputs.size());
-        unsigned int m = 0;
-        for (auto & j : outputs) {
-            mkString(*(vOutputs.listElems()[m++] = state.allocValue()), j.first);
-            Value & vOutputs = *state.allocAttr(v, state.symbols.create(j.first));
-            state.mkAttrs(vOutputs, 2);
-            mkString(*state.allocAttr(vOutputs, state.sOutPath), j.second);
-
-            /* This is only necessary when installing store paths, e.g.,
-               `nix-env -i /nix/store/abcd...-foo'. */
-            state.store->addTempRoot(j.second);
-            state.store->ensurePath(j.second);
-
-            references.insert(j.second);
-        }
-
-        // Copy the meta attributes.
-        Value & vMeta = *state.allocAttr(v, state.sMeta);
-        state.mkAttrs(vMeta, 16);
-        StringSet metaNames = i.queryMetaNames();
-        for (auto & j : metaNames) {
-            Value * v = i.queryMeta(j);
-            if (!v) continue;
-            vMeta.attrs->push_back(Attr(state.symbols.create(j), v));
-        }
-        vMeta.attrs->sort();
-        v.attrs->sort();
-
-        if (drvPath != "") references.insert(drvPath);
+bool createUserEnv(EvalState& state, DrvInfos& elems, const Path& profile,
+                   bool keepDerivations, const string& lockToken) {
+  /* Build the components in the user environment, if they don't
+     exist already. */
+  PathSet drvsToBuild;
+  for (auto& i : elems)
+    if (i.queryDrvPath() != "") drvsToBuild.insert(i.queryDrvPath());
+
+  debug(format("building user environment dependencies"));
+  state.store->buildPaths(drvsToBuild, state.repair ? bmRepair : bmNormal);
+
+  /* Construct the whole top level derivation. */
+  PathSet references;
+  Value manifest;
+  state.mkList(manifest, elems.size());
+  unsigned int n = 0;
+  for (auto& i : elems) {
+    /* Create a pseudo-derivation containing the name, system,
+       output paths, and optionally the derivation path, as well
+       as the meta attributes. */
+    Path drvPath = keepDerivations ? i.queryDrvPath() : "";
+
+    Value& v(*state.allocValue());
+    manifest.listElems()[n++] = &v;
+    state.mkAttrs(v, 16);
+
+    mkString(*state.allocAttr(v, state.sType), "derivation");
+    mkString(*state.allocAttr(v, state.sName), i.queryName());
+    auto system = i.querySystem();
+    if (!system.empty()) mkString(*state.allocAttr(v, state.sSystem), system);
+    mkString(*state.allocAttr(v, state.sOutPath), i.queryOutPath());
+    if (drvPath != "")
+      mkString(*state.allocAttr(v, state.sDrvPath), i.queryDrvPath());
+
+    // Copy each output meant for installation.
+    DrvInfo::Outputs outputs = i.queryOutputs(true);
+    Value& vOutputs = *state.allocAttr(v, state.sOutputs);
+    state.mkList(vOutputs, outputs.size());
+    unsigned int m = 0;
+    for (auto& j : outputs) {
+      mkString(*(vOutputs.listElems()[m++] = state.allocValue()), j.first);
+      Value& vOutputs = *state.allocAttr(v, state.symbols.create(j.first));
+      state.mkAttrs(vOutputs, 2);
+      mkString(*state.allocAttr(vOutputs, state.sOutPath), j.second);
+
+      /* This is only necessary when installing store paths, e.g.,
+         `nix-env -i /nix/store/abcd...-foo'. */
+      state.store->addTempRoot(j.second);
+      state.store->ensurePath(j.second);
+
+      references.insert(j.second);
     }
 
-    /* Also write a copy of the list of user environment elements to
-       the store; we need it for future modifications of the
-       environment. */
-    Path manifestFile = state.store->addTextToStore("env-manifest.nix",
-        (format("%1%") % manifest).str(), references);
-
-    /* Get the environment builder expression. */
-    Value envBuilder;
-    state.evalFile(state.findFile("nix/buildenv.nix"), envBuilder);
-
-    /* Construct a Nix expression that calls the user environment
-       builder with the manifest as argument. */
-    Value args, topLevel;
-    state.mkAttrs(args, 3);
-    mkString(*state.allocAttr(args, state.symbols.create("manifest")),
-        manifestFile, {manifestFile});
-    args.attrs->push_back(Attr(state.symbols.create("derivations"), &manifest));
-    args.attrs->sort();
-    mkApp(topLevel, envBuilder, args);
-
-    /* Evaluate it. */
-    debug("evaluating user environment builder");
-    state.forceValue(topLevel);
-    PathSet context;
-    Attr & aDrvPath(*topLevel.attrs->find(state.sDrvPath));
-    Path topLevelDrv = state.coerceToPath(aDrvPath.pos ? *(aDrvPath.pos) : noPos, *(aDrvPath.value), context);
-    Attr & aOutPath(*topLevel.attrs->find(state.sOutPath));
-    Path topLevelOut = state.coerceToPath(aOutPath.pos ? *(aOutPath.pos) : noPos, *(aOutPath.value), context);
-
-    /* Realise the resulting store expression. */
-    debug("building user environment");
-    state.store->buildPaths({topLevelDrv}, state.repair ? bmRepair : bmNormal);
-
-    /* Switch the current user environment to the output path. */
-    auto store2 = state.store.dynamic_pointer_cast<LocalFSStore>();
-
-    if (store2) {
-        PathLocks lock;
-        lockProfile(lock, profile);
-
-        Path lockTokenCur = optimisticLockProfile(profile);
-        if (lockToken != lockTokenCur) {
-            printError(format("profile '%1%' changed while we were busy; restarting") % profile);
-            return false;
-        }
-
-        debug(format("switching to new user environment"));
-        Path generation = createGeneration(ref<LocalFSStore>(store2), profile, topLevelOut);
-        switchLink(profile, generation);
+    // Copy the meta attributes.
+    Value& vMeta = *state.allocAttr(v, state.sMeta);
+    state.mkAttrs(vMeta, 16);
+    StringSet metaNames = i.queryMetaNames();
+    for (auto& j : metaNames) {
+      Value* v = i.queryMeta(j);
+      if (!v) continue;
+      vMeta.attrs->push_back(Attr(state.symbols.create(j), v));
+    }
+    vMeta.attrs->sort();
+    v.attrs->sort();
+
+    if (drvPath != "") references.insert(drvPath);
+  }
+
+  /* Also write a copy of the list of user environment elements to
+     the store; we need it for future modifications of the
+     environment. */
+  Path manifestFile = state.store->addTextToStore(
+      "env-manifest.nix", (format("%1%") % manifest).str(), references);
+
+  /* Get the environment builder expression. */
+  Value envBuilder;
+  state.evalFile(state.findFile("nix/buildenv.nix"), envBuilder);
+
+  /* Construct a Nix expression that calls the user environment
+     builder with the manifest as argument. */
+  Value args, topLevel;
+  state.mkAttrs(args, 3);
+  mkString(*state.allocAttr(args, state.symbols.create("manifest")),
+           manifestFile, {manifestFile});
+  args.attrs->push_back(Attr(state.symbols.create("derivations"), &manifest));
+  args.attrs->sort();
+  mkApp(topLevel, envBuilder, args);
+
+  /* Evaluate it. */
+  debug("evaluating user environment builder");
+  state.forceValue(topLevel);
+  PathSet context;
+  Attr& aDrvPath(*topLevel.attrs->find(state.sDrvPath));
+  Path topLevelDrv = state.coerceToPath(aDrvPath.pos ? *(aDrvPath.pos) : noPos,
+                                        *(aDrvPath.value), context);
+  Attr& aOutPath(*topLevel.attrs->find(state.sOutPath));
+  Path topLevelOut = state.coerceToPath(aOutPath.pos ? *(aOutPath.pos) : noPos,
+                                        *(aOutPath.value), context);
+
+  /* Realise the resulting store expression. */
+  debug("building user environment");
+  state.store->buildPaths({topLevelDrv}, state.repair ? bmRepair : bmNormal);
+
+  /* Switch the current user environment to the output path. */
+  auto store2 = state.store.dynamic_pointer_cast<LocalFSStore>();
+
+  if (store2) {
+    PathLocks lock;
+    lockProfile(lock, profile);
+
+    Path lockTokenCur = optimisticLockProfile(profile);
+    if (lockToken != lockTokenCur) {
+      printError(
+          format("profile '%1%' changed while we were busy; restarting") %
+          profile);
+      return false;
     }
 
-    return true;
-}
-
+    debug(format("switching to new user environment"));
+    Path generation =
+        createGeneration(ref<LocalFSStore>(store2), profile, topLevelOut);
+    switchLink(profile, generation);
+  }
 
+  return true;
 }
+
+}  // namespace nix
diff --git a/third_party/nix/src/nix-env/user-env.hh b/third_party/nix/src/nix-env/user-env.hh
index f188efe9b4a9..6111b21c353d 100644
--- a/third_party/nix/src/nix-env/user-env.hh
+++ b/third_party/nix/src/nix-env/user-env.hh
@@ -4,10 +4,9 @@
 
 namespace nix {
 
-DrvInfos queryInstalled(EvalState & state, const Path & userEnv);
+DrvInfos queryInstalled(EvalState& state, const Path& userEnv);
 
-bool createUserEnv(EvalState & state, DrvInfos & elems,
-    const Path & profile, bool keepDerivations,
-    const string & lockToken);
+bool createUserEnv(EvalState& state, DrvInfos& elems, const Path& profile,
+                   bool keepDerivations, const string& lockToken);
 
-}
+}  // namespace nix