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-rw-r--r--third_party/nix/src/libstore/binary-cache-store.cc5
-rw-r--r--third_party/nix/src/libstore/binary-cache-store.hh6
-rw-r--r--third_party/nix/src/libstore/build.cc131
-rw-r--r--third_party/nix/src/libstore/builtins/buildenv.cc4
-rw-r--r--third_party/nix/src/libstore/builtins/fetchurl.cc2
-rw-r--r--third_party/nix/src/libstore/crypto.cc8
-rw-r--r--third_party/nix/src/libstore/derivations.cc60
-rw-r--r--third_party/nix/src/libstore/derivations.hh28
-rw-r--r--third_party/nix/src/libstore/download.cc29
-rw-r--r--third_party/nix/src/libstore/download.hh2
-rw-r--r--third_party/nix/src/libstore/gc.cc38
-rw-r--r--third_party/nix/src/libstore/globals.cc2
-rw-r--r--third_party/nix/src/libstore/globals.hh2
-rw-r--r--third_party/nix/src/libstore/http-binary-cache-store.cc2
-rw-r--r--third_party/nix/src/libstore/legacy-ssh-store.cc10
-rw-r--r--third_party/nix/src/libstore/local-fs-store.cc11
-rw-r--r--third_party/nix/src/libstore/local-store.cc43
-rw-r--r--third_party/nix/src/libstore/local-store.hh14
-rw-r--r--third_party/nix/src/libstore/machines.cc24
-rw-r--r--third_party/nix/src/libstore/machines.hh14
-rw-r--r--third_party/nix/src/libstore/nar-accessor.cc6
-rw-r--r--third_party/nix/src/libstore/nar-info.cc2
-rw-r--r--third_party/nix/src/libstore/optimise-store.cc4
-rw-r--r--third_party/nix/src/libstore/pathlocks.cc4
-rw-r--r--third_party/nix/src/libstore/pathlocks.hh6
-rw-r--r--third_party/nix/src/libstore/profiles.cc22
-rw-r--r--third_party/nix/src/libstore/profiles.hh8
-rw-r--r--third_party/nix/src/libstore/references.cc30
-rw-r--r--third_party/nix/src/libstore/remote-store.cc14
-rw-r--r--third_party/nix/src/libstore/remote-store.hh6
-rw-r--r--third_party/nix/src/libstore/s3-binary-cache-store.cc7
-rw-r--r--third_party/nix/src/libstore/sqlite.cc2
-rw-r--r--third_party/nix/src/libstore/store-api.cc64
-rw-r--r--third_party/nix/src/libstore/store-api.hh52
34 files changed, 336 insertions, 326 deletions
diff --git a/third_party/nix/src/libstore/binary-cache-store.cc b/third_party/nix/src/libstore/binary-cache-store.cc
index 487c12b531..37d1c1a440 100644
--- a/third_party/nix/src/libstore/binary-cache-store.cc
+++ b/third_party/nix/src/libstore/binary-cache-store.cc
@@ -289,7 +289,7 @@ void BinaryCacheStore::queryPathInfoUncached(
           }});
 }
 
-Path BinaryCacheStore::addToStore(const string& name, const Path& srcPath,
+Path BinaryCacheStore::addToStore(const std::string& name, const Path& srcPath,
                                   bool recursive, HashType hashAlgo,
                                   PathFilter& filter, RepairFlag repair) {
   // FIXME: some cut&paste from LocalStore::addToStore().
@@ -316,7 +316,8 @@ Path BinaryCacheStore::addToStore(const string& name, const Path& srcPath,
   return info.path;
 }
 
-Path BinaryCacheStore::addTextToStore(const string& name, const string& s,
+Path BinaryCacheStore::addTextToStore(const std::string& name,
+                                      const std::string& s,
                                       const PathSet& references,
                                       RepairFlag repair) {
   ValidPathInfo info;
diff --git a/third_party/nix/src/libstore/binary-cache-store.hh b/third_party/nix/src/libstore/binary-cache-store.hh
index f5bd66bbd6..b8e1ccabf2 100644
--- a/third_party/nix/src/libstore/binary-cache-store.hh
+++ b/third_party/nix/src/libstore/binary-cache-store.hh
@@ -74,7 +74,7 @@ class BinaryCacheStore : public Store {
       const Path& path,
       Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override;
 
-  Path queryPathFromHashPart(const string& hashPart) override {
+  Path queryPathFromHashPart(const std::string& hashPart) override {
     unsupported("queryPathFromHashPart");
   }
 
@@ -84,11 +84,11 @@ class BinaryCacheStore : public Store {
                   RepairFlag repair, CheckSigsFlag checkSigs,
                   std::shared_ptr<FSAccessor> accessor) override;
 
-  Path addToStore(const string& name, const Path& srcPath, bool recursive,
+  Path addToStore(const std::string& name, const Path& srcPath, bool recursive,
                   HashType hashAlgo, PathFilter& filter,
                   RepairFlag repair) override;
 
-  Path addTextToStore(const string& name, const string& s,
+  Path addTextToStore(const std::string& name, const std::string& s,
                       const PathSet& references, RepairFlag repair) override;
 
   void narFromPath(const Path& path, Sink& sink) override;
diff --git a/third_party/nix/src/libstore/build.cc b/third_party/nix/src/libstore/build.cc
index 266cedc096..49204a72a8 100644
--- a/third_party/nix/src/libstore/build.cc
+++ b/third_party/nix/src/libstore/build.cc
@@ -73,9 +73,7 @@
 
 namespace nix {
 
-using std::map;
-
-static string pathNullDevice = "/dev/null";
+static std::string pathNullDevice = "/dev/null";
 
 /* Forward definition. */
 class Worker;
@@ -92,11 +90,11 @@ struct CompareGoalPtrs {
 };
 
 /* Set of goals. */
-typedef set<GoalPtr, CompareGoalPtrs> Goals;
-using WeakGoals = list<WeakGoalPtr>;
+typedef std::set<GoalPtr, CompareGoalPtrs> Goals;
+using WeakGoals = std::list<WeakGoalPtr>;
 
 /* A map of paths to goals (and the other way around). */
-typedef map<Path, WeakGoalPtr> WeakGoalMap;
+typedef std::map<Path, WeakGoalPtr> WeakGoalMap;
 
 class Goal : public std::enable_shared_from_this<Goal> {
  public:
@@ -131,7 +129,7 @@ class Goal : public std::enable_shared_from_this<Goal> {
   unsigned int nrIncompleteClosure;
 
   /* Name of this goal for debugging purposes. */
-  string name;
+  std::string name;
 
   /* Whether the goal is finished. */
   ExitCode exitCode;
@@ -150,13 +148,13 @@ class Goal : public std::enable_shared_from_this<Goal> {
 
   virtual void waiteeDone(GoalPtr waitee, ExitCode result);
 
-  virtual void handleChildOutput(int fd, const string& data) { abort(); }
+  virtual void handleChildOutput(int fd, const std::string& data) { abort(); }
 
   virtual void handleEOF(int fd) { abort(); }
 
   void trace(const FormatOrString& fs);
 
-  string getName() { return name; }
+  std::string getName() { return name; }
 
   ExitCode getExitCode() { return exitCode; }
 
@@ -165,15 +163,15 @@ class Goal : public std::enable_shared_from_this<Goal> {
      by the worker (important!), etc. */
   virtual void timedOut() = 0;
 
-  virtual string key() = 0;
+  virtual std::string key() = 0;
 
  protected:
   virtual void amDone(ExitCode result);
 };
 
 bool CompareGoalPtrs::operator()(const GoalPtr& a, const GoalPtr& b) const {
-  string s1 = a->key();
-  string s2 = b->key();
+  std::string s1 = a->key();
+  std::string s2 = b->key();
   return s1 < s2;
 }
 
@@ -185,7 +183,7 @@ using steady_time_point = std::chrono::time_point<std::chrono::steady_clock>;
 struct Child {
   WeakGoalPtr goal;
   Goal* goal2;  // ugly hackery
-  set<int> fds;
+  std::set<int> fds;
   bool respectTimeouts;
   bool inBuildSlot;
   steady_time_point lastOutput; /* time we last got output on stdout/stderr */
@@ -293,8 +291,8 @@ class Worker {
 
   /* Registers a running child process.  `inBuildSlot' means that
      the process counts towards the jobs limit. */
-  void childStarted(const GoalPtr& goal, const set<int>& fds, bool inBuildSlot,
-                    bool respectTimeouts);
+  void childStarted(const GoalPtr& goal, const std::set<int>& fds,
+                    bool inBuildSlot, bool respectTimeouts);
 
   /* Unregisters a running child process.  `wakeSleepers' should be
      false if there is no sense in waking up goals that are sleeping
@@ -483,7 +481,7 @@ class UserLock {
   Path fnUserLock;
   AutoCloseFD fdUserLock;
 
-  string user;
+  std::string user;
   uid_t uid;
   gid_t gid;
   std::vector<gid_t> supplementaryGIDs;
@@ -494,7 +492,7 @@ class UserLock {
 
   void kill();
 
-  string getUser() { return user; }
+  std::string getUser() { return user; }
   uid_t getUID() {
     assert(uid);
     return uid;
@@ -710,12 +708,12 @@ HookInstance::~HookInstance() {
 
 //////////////////////////////////////////////////////////////////////
 
-typedef map<std::string, std::string> StringRewrites;
+typedef std::map<std::string, std::string> StringRewrites;
 
 std::string rewriteStrings(std::string s, const StringRewrites& rewrites) {
   for (auto& i : rewrites) {
     size_t j = 0;
-    while ((j = s.find(i.first, j)) != string::npos) {
+    while ((j = s.find(i.first, j)) != std::string::npos) {
       s.replace(j, i.first.size(), i.second);
     }
   }
@@ -831,16 +829,16 @@ class DerivationGoal : public Goal {
     explicit ChrootPath(Path source = "", bool optional = false)
         : source(std::move(source)), optional(optional) {}
   };
-  typedef map<Path, ChrootPath>
+  typedef std::map<Path, ChrootPath>
       DirsInChroot;  // maps target path to source path
   DirsInChroot dirsInChroot;
 
-  typedef map<string, string> Environment;
+  typedef std::map<std::string, std::string> Environment;
   Environment env;
 
   /* Hash rewriting. */
   StringRewrites inputRewrites, outputRewrites;
-  typedef map<Path, Path> RedirectedOutputs;
+  typedef std::map<Path, Path> RedirectedOutputs;
   RedirectedOutputs redirectedOutputs;
 
   BuildMode buildMode;
@@ -886,7 +884,7 @@ class DerivationGoal : public Goal {
 
   void timedOut() override;
 
-  string key() override {
+  std::string key() override {
     /* Ensure that derivations get built in order of their name,
        i.e. a derivation named "aardvark" always comes before
        "baboon". And substitution goals always happen before
@@ -956,7 +954,7 @@ class DerivationGoal : public Goal {
   void deleteTmpDir(bool force);
 
   /* Callback used by the worker to write to the log. */
-  void handleChildOutput(int fd, const string& data) override;
+  void handleChildOutput(int fd, const std::string& data) override;
   void handleEOF(int fd) override;
   void flushLine();
 
@@ -975,7 +973,7 @@ class DerivationGoal : public Goal {
 
   void amDone(ExitCode result) override { Goal::amDone(result); }
 
-  void done(BuildResult::Status status, const string& msg = "");
+  void done(BuildResult::Status status, const std::string& msg = "");
 
   PathSet exportReferences(const PathSet& storePaths);
 };
@@ -1036,9 +1034,7 @@ DerivationGoal::~DerivationGoal() {
   }
 }
 
-inline bool DerivationGoal::needsHashRewrite() {
-  return !useChroot;
-}
+inline bool DerivationGoal::needsHashRewrite() { return !useChroot; }
 
 void DerivationGoal::killChild() {
   if (pid != -1) {
@@ -1762,11 +1758,11 @@ HookReply DerivationGoal::tryBuildHook() {
 
     /* Read the first line of input, which should be a word indicating
        whether the hook wishes to perform the build. */
-    string reply;
+    std::string reply;
     while (true) {
-      string s = readLine(worker.hook->fromHook.readSide.get());
-      if (string(s, 0, 2) == "# ") {
-        reply = string(s, 2);
+      std::string s = readLine(worker.hook->fromHook.readSide.get());
+      if (std::string(s, 0, 2) == "# ") {
+        reply = std::string(s, 2);
         break;
       }
       s += "\n";
@@ -1816,7 +1812,7 @@ HookReply DerivationGoal::tryBuildHook() {
   /* Create the log file and pipe. */
   Path logFile = openLogFile();
 
-  set<int> fds;
+  std::set<int> fds;
   fds.insert(hook->fromHook.readSide.get());
   fds.insert(hook->builderOut.readSide.get());
   worker.childStarted(shared_from_this(), fds, false, false);
@@ -1970,14 +1966,14 @@ void DerivationGoal::startBuilder() {
        temporary build directory.  The text files have the format used
        by `nix-store --register-validity'.  However, the deriver
        fields are left empty. */
-    string s = get(drv->env, "exportReferencesGraph");
+    std::string s = get(drv->env, "exportReferencesGraph");
     auto ss = tokenizeString<Strings>(s);
     if (ss.size() % 2 != 0) {
       throw BuildError(
           format("odd number of tokens in 'exportReferencesGraph': '%1%'") % s);
     }
     for (auto i = ss.begin(); i != ss.end();) {
-      string fileName = *i++;
+      std::string fileName = *i++;
       checkStoreName(fileName); /* !!! abuse of this function */
       Path storePath = *i++;
 
@@ -2007,10 +2003,11 @@ void DerivationGoal::startBuilder() {
         i.pop_back();
       }
       size_t p = i.find('=');
-      if (p == string::npos) {
+      if (p == std::string::npos) {
         dirsInChroot[i] = ChrootPath(i, optional);
       } else {
-        dirsInChroot[string(i, 0, p)] = ChrootPath(string(i, p + 1), optional);
+        dirsInChroot[std::string(i, 0, p)] =
+            ChrootPath(std::string(i, p + 1), optional);
       }
     }
     dirsInChroot[tmpDirInSandbox] = ChrootPath(tmpDir);
@@ -2211,7 +2208,7 @@ void DerivationGoal::startBuilder() {
     auto state = stBegin;
     auto lines = runProgram(settings.preBuildHook, false, args);
     auto lastPos = std::string::size_type{0};
-    for (auto nlPos = lines.find('\n'); nlPos != string::npos;
+    for (auto nlPos = lines.find('\n'); nlPos != std::string::npos;
          nlPos = lines.find('\n', lastPos)) {
       auto line = std::string{lines, lastPos, nlPos - lastPos};
       lastPos = nlPos + 1;
@@ -2226,10 +2223,11 @@ void DerivationGoal::startBuilder() {
           state = stBegin;
         } else {
           auto p = line.find('=');
-          if (p == string::npos) {
+          if (p == std::string::npos) {
             dirsInChroot[line] = ChrootPath(line);
           } else {
-            dirsInChroot[string(line, 0, p)] = ChrootPath(string(line, p + 1));
+            dirsInChroot[std::string(line, 0, p)] =
+                ChrootPath(std::string(line, p + 1));
           }
         }
       }
@@ -2454,12 +2452,12 @@ void DerivationGoal::startBuilder() {
 
   /* Check if setting up the build environment failed. */
   while (true) {
-    string msg = readLine(builderOut.readSide.get());
-    if (string(msg, 0, 1) == "\1") {
+    std::string msg = readLine(builderOut.readSide.get());
+    if (std::string(msg, 0, 1) == "\1") {
       if (msg.size() == 1) {
         break;
       }
-      throw Error(string(msg, 1));
+      throw Error(std::string(msg, 1));
     }
     DLOG(INFO) << msg;
   }
@@ -2488,7 +2486,7 @@ void DerivationGoal::initTmpDir() {
       if (passAsFile.find(i.first) == passAsFile.end()) {
         env[i.first] = i.second;
       } else {
-        string fn = ".attr-" + std::to_string(fileNr++);
+        std::string fn = ".attr-" + std::to_string(fileNr++);
         Path p = tmpDir + "/" + fn;
         writeFile(p, rewriteStrings(i.second, inputRewrites));
         chownToBuilder(p);
@@ -3110,7 +3108,7 @@ void DerivationGoal::runChild() {
 
     if (!drv->isBuiltin()) {
       builder = drv->builder.c_str();
-      string builderBasename = baseNameOf(drv->builder);
+      std::string builderBasename = baseNameOf(drv->builder);
       args.push_back(builderBasename);
     }
 
@@ -3119,7 +3117,7 @@ void DerivationGoal::runChild() {
     }
 
     /* Indicate that we managed to set up the build environment. */
-    writeFull(STDERR_FILENO, string("\1\n"));
+    writeFull(STDERR_FILENO, std::string("\1\n"));
 
     /* Execute the program.  This should not return. */
     if (drv->isBuiltin()) {
@@ -3135,11 +3133,11 @@ void DerivationGoal::runChild() {
           builtinBuildenv(drv2);
         } else {
           throw Error(format("unsupported builtin function '%1%'") %
-                      string(drv->builder, 8));
+                      std::string(drv->builder, 8));
         }
         _exit(0);
       } catch (std::exception& e) {
-        writeFull(STDERR_FILENO, "error: " + string(e.what()) + "\n");
+        writeFull(STDERR_FILENO, "error: " + std::string(e.what()) + "\n");
         _exit(1);
       }
     }
@@ -3151,7 +3149,7 @@ void DerivationGoal::runChild() {
 
   } catch (std::exception& e) {
     writeFull(STDERR_FILENO, "\1while setting up the build environment: " +
-                                 string(e.what()) + "\n");
+                                 std::string(e.what()) + "\n");
     _exit(1);
   }
 }
@@ -3621,7 +3619,7 @@ void DerivationGoal::checkOutputs(
         }
 
         if (!badPaths.empty()) {
-          string badPathsStr;
+          std::string badPathsStr;
           for (auto& i : badPaths) {
             badPathsStr += "\n  ";
             badPathsStr += i;
@@ -3705,14 +3703,14 @@ Path DerivationGoal::openLogFile() {
     return "";
   }
 
-  string baseName = baseNameOf(drvPath);
+  std::string baseName = baseNameOf(drvPath);
 
   /* Create a log file. */
   Path dir = fmt("%s/%s/%s/", worker.store.logDir, nix::LocalStore::drvsLogDir,
-                 string(baseName, 0, 2));
+                 std::string(baseName, 0, 2));
   createDirs(dir);
 
-  Path logFileName = fmt("%s/%s%s", dir, string(baseName, 2),
+  Path logFileName = fmt("%s/%s%s", dir, std::string(baseName, 2),
                          settings.compressLog ? ".bz2" : "");
 
   fdLogFile =
@@ -3759,7 +3757,7 @@ void DerivationGoal::deleteTmpDir(bool force) {
   }
 }
 
-void DerivationGoal::handleChildOutput(int fd, const string& data) {
+void DerivationGoal::handleChildOutput(int fd, const std::string& data) {
   if ((hook && fd == hook->builderOut.readSide.get()) ||
       (!hook && fd == builderOut.readSide.get())) {
     logSize += data.size();
@@ -3839,12 +3837,13 @@ PathSet DerivationGoal::checkPathValidity(bool returnValid, bool checkHash) {
 }
 
 Path DerivationGoal::addHashRewrite(const Path& path) {
-  string h1 = string(path, worker.store.storeDir.size() + 1, 32);
-  string h2 = string(hashString(htSHA256, "rewrite:" + drvPath + ":" + path)
-                         .to_string(Base32, false),
-                     0, 32);
+  std::string h1 = std::string(path, worker.store.storeDir.size() + 1, 32);
+  std::string h2 =
+      std::string(hashString(htSHA256, "rewrite:" + drvPath + ":" + path)
+                      .to_string(Base32, false),
+                  0, 32);
   Path p = worker.store.storeDir + "/" + h2 +
-           string(path, worker.store.storeDir.size() + 33);
+           std::string(path, worker.store.storeDir.size() + 33);
   deletePath(p);
   assert(path.size() == p.size());
   inputRewrites[h1] = h2;
@@ -3853,7 +3852,7 @@ Path DerivationGoal::addHashRewrite(const Path& path) {
   return p;
 }
 
-void DerivationGoal::done(BuildResult::Status status, const string& msg) {
+void DerivationGoal::done(BuildResult::Status status, const std::string& msg) {
   result.status = status;
   result.errorMsg = msg;
   amDone(result.success() ? ecSuccess : ecFailed);
@@ -3928,7 +3927,7 @@ class SubstitutionGoal : public Goal {
 
   void timedOut() override { abort(); };
 
-  string key() override {
+  std::string key() override {
     /* "a$" ensures substitution goals happen before derivation
        goals. */
     return "a$" + storePathToName(storePath) + "$" + storePath;
@@ -3945,7 +3944,7 @@ class SubstitutionGoal : public Goal {
   void finished();
 
   /* Callback used by the worker to write to the log. */
-  void handleChildOutput(int fd, const string& data) override;
+  void handleChildOutput(int fd, const std::string& data) override;
   void handleEOF(int fd) override;
 
   Path getStorePath() { return storePath; }
@@ -4204,7 +4203,7 @@ void SubstitutionGoal::finished() {
   amDone(ecSuccess);
 }
 
-void SubstitutionGoal::handleChildOutput(int fd, const string& data) {}
+void SubstitutionGoal::handleChildOutput(int fd, const std::string& data) {}
 
 void SubstitutionGoal::handleEOF(int fd) {
   if (fd == outPipe.readSide.get()) {
@@ -4321,7 +4320,7 @@ void Worker::wakeUp(const GoalPtr& goal) {
 
 unsigned Worker::getNrLocalBuilds() { return nrLocalBuilds; }
 
-void Worker::childStarted(const GoalPtr& goal, const set<int>& fds,
+void Worker::childStarted(const GoalPtr& goal, const std::set<int>& fds,
                           bool inBuildSlot, bool respectTimeouts) {
   Child child;
   child.goal = goal;
@@ -4545,7 +4544,7 @@ void Worker::waitForInput() {
     GoalPtr goal = j->goal.lock();
     assert(goal);
 
-    set<int> fds2(j->fds);
+    std::set<int> fds2(j->fds);
     std::vector<unsigned char> buffer(4096);
     for (auto& k : fds2) {
       if (FD_ISSET(k, &fds)) {
@@ -4562,7 +4561,7 @@ void Worker::waitForInput() {
           }
         } else {
           DLOG(INFO) << goal->getName() << ": read " << rd << " bytes";
-          string data((char*)buffer.data(), rd);
+          std::string data((char*)buffer.data(), rd);
           j->lastOutput = after;
           goal->handleChildOutput(k, data);
         }
diff --git a/third_party/nix/src/libstore/builtins/buildenv.cc b/third_party/nix/src/libstore/builtins/buildenv.cc
index 77ad722fab..d14474a93d 100644
--- a/third_party/nix/src/libstore/builtins/buildenv.cc
+++ b/third_party/nix/src/libstore/builtins/buildenv.cc
@@ -133,7 +133,7 @@ static void addPkg(const Path& pkgDir, int priority) {
   createLinks(pkgDir, out, priority);
 
   try {
-    for (const auto& p : tokenizeString<std::vector<string>>(
+    for (const auto& p : tokenizeString<std::vector<std::string>>(
              readFile(pkgDir + "/nix-support/propagated-user-env-packages"),
              " \n"))
       if (!done.count(p)) {
@@ -157,7 +157,7 @@ struct Package {
 typedef std::vector<Package> Packages;
 
 void builtinBuildenv(const BasicDerivation& drv) {
-  auto getAttr = [&](const string& name) {
+  auto getAttr = [&](const std::string& name) {
     auto i = drv.env.find(name);
     if (i == drv.env.end()) {
       throw Error("attribute '%s' missing", name);
diff --git a/third_party/nix/src/libstore/builtins/fetchurl.cc b/third_party/nix/src/libstore/builtins/fetchurl.cc
index c3f38a943f..97260d2e52 100644
--- a/third_party/nix/src/libstore/builtins/fetchurl.cc
+++ b/third_party/nix/src/libstore/builtins/fetchurl.cc
@@ -17,7 +17,7 @@ void builtinFetchurl(const BasicDerivation& drv, const std::string& netrcData) {
     writeFile(settings.netrcFile, netrcData, 0600);
   }
 
-  auto getAttr = [&](const string& name) {
+  auto getAttr = [&](const std::string& name) {
     auto i = drv.env.find(name);
     if (i == drv.env.end())
       throw Error(format("attribute '%s' missing") % name);
diff --git a/third_party/nix/src/libstore/crypto.cc b/third_party/nix/src/libstore/crypto.cc
index 90580b8dc9..eb5bb66707 100644
--- a/third_party/nix/src/libstore/crypto.cc
+++ b/third_party/nix/src/libstore/crypto.cc
@@ -9,7 +9,7 @@
 
 namespace nix {
 
-static std::pair<std::string, std::string> split(const string& s) {
+static std::pair<std::string, std::string> split(const std::string& s) {
   size_t colon = s.find(':');
   if (colon == std::string::npos || colon == 0) {
     return {"", ""};
@@ -17,7 +17,7 @@ static std::pair<std::string, std::string> split(const string& s) {
   return {std::string(s, 0, colon), std::string(s, colon + 1)};
 }
 
-Key::Key(const string& s) {
+Key::Key(const std::string& s) {
   auto ss = split(s);
 
   name = ss.first;
@@ -30,7 +30,7 @@ Key::Key(const string& s) {
   key = base64Decode(key);
 }
 
-SecretKey::SecretKey(const string& s) : Key(s) {
+SecretKey::SecretKey(const std::string& s) : Key(s) {
 #if HAVE_SODIUM
   if (key.size() != crypto_sign_SECRETKEYBYTES) {
     throw Error("secret key is not valid");
@@ -68,7 +68,7 @@ PublicKey SecretKey::toPublicKey() const {
 #endif
 }
 
-PublicKey::PublicKey(const string& s) : Key(s) {
+PublicKey::PublicKey(const std::string& s) : Key(s) {
 #if HAVE_SODIUM
   if (key.size() != crypto_sign_PUBLICKEYBYTES) {
     throw Error("public key is not valid");
diff --git a/third_party/nix/src/libstore/derivations.cc b/third_party/nix/src/libstore/derivations.cc
index 9c71d7209e..f8770327bf 100644
--- a/third_party/nix/src/libstore/derivations.cc
+++ b/third_party/nix/src/libstore/derivations.cc
@@ -11,11 +11,11 @@ namespace nix {
 
 void DerivationOutput::parseHashInfo(bool& recursive, Hash& hash) const {
   recursive = false;
-  string algo = hashAlgo;
+  std::string algo = hashAlgo;
 
-  if (string(algo, 0, 2) == "r:") {
+  if (std::string(algo, 0, 2) == "r:") {
     recursive = true;
-    algo = string(algo, 2);
+    algo = std::string(algo, 2);
   }
 
   HashType hashType = parseHashType(algo);
@@ -26,7 +26,7 @@ void DerivationOutput::parseHashInfo(bool& recursive, Hash& hash) const {
   hash = Hash(this->hash, hashType);
 }
 
-Path BasicDerivation::findOutput(const string& id) const {
+Path BasicDerivation::findOutput(const std::string& id) const {
   auto i = outputs.find(id);
   if (i == outputs.end()) {
     throw Error(format("derivation has no output '%1%'") % id);
@@ -35,11 +35,11 @@ Path BasicDerivation::findOutput(const string& id) const {
 }
 
 bool BasicDerivation::isBuiltin() const {
-  return string(builder, 0, 8) == "builtin:";
+  return std::string(builder, 0, 8) == "builtin:";
 }
 
 Path writeDerivation(const ref<Store>& store, const Derivation& drv,
-                     const string& name, RepairFlag repair) {
+                     const std::string& name, RepairFlag repair) {
   PathSet references;
   references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
   for (auto& i : drv.inputDrvs) {
@@ -48,25 +48,25 @@ Path writeDerivation(const ref<Store>& store, const Derivation& drv,
   /* Note that the outputs of a derivation are *not* references
      (that can be missing (of course) and should not necessarily be
      held during a garbage collection). */
-  string suffix = name + drvExtension;
-  string contents = drv.unparse();
+  std::string suffix = name + drvExtension;
+  std::string contents = drv.unparse();
   return settings.readOnlyMode
              ? store->computeStorePathForText(suffix, contents, references)
              : store->addTextToStore(suffix, contents, references, repair);
 }
 
 /* Read string `s' from stream `str'. */
-static void expect(std::istream& str, const string& s) {
+static void expect(std::istream& str, const std::string& s) {
   char s2[s.size()];
   str.read(s2, s.size());
-  if (string(s2, s.size()) != s) {
+  if (std::string(s2, s.size()) != s) {
     throw FormatError(format("expected string '%1%'") % s);
   }
 }
 
 /* Read a C-style string from stream `str'. */
-static string parseString(std::istream& str) {
-  string res;
+static std::string parseString(std::istream& str) {
+  std::string res;
   expect(str, "\"");
   int c;
   while ((c = str.get()) != '"') {
@@ -89,7 +89,7 @@ static string parseString(std::istream& str) {
 }
 
 static Path parsePath(std::istream& str) {
-  string s = parseString(str);
+  std::string s = parseString(str);
   if (s.empty() || s[0] != '/') {
     throw FormatError(format("bad path '%1%' in derivation") % s);
   }
@@ -116,7 +116,7 @@ static StringSet parseStrings(std::istream& str, bool arePaths) {
   return res;
 }
 
-static Derivation parseDerivation(const string& s) {
+static Derivation parseDerivation(const std::string& s) {
   Derivation drv;
   istringstream_nocopy str(s);
   expect(str, "Derive([");
@@ -125,7 +125,7 @@ static Derivation parseDerivation(const string& s) {
   while (!endOfList(str)) {
     DerivationOutput out;
     expect(str, "(");
-    string id = parseString(str);
+    std::string id = parseString(str);
     expect(str, ",");
     out.path = parsePath(str);
     expect(str, ",");
@@ -163,9 +163,9 @@ static Derivation parseDerivation(const string& s) {
   expect(str, ",[");
   while (!endOfList(str)) {
     expect(str, "(");
-    string name = parseString(str);
+    std::string name = parseString(str);
     expect(str, ",");
-    string value = parseString(str);
+    std::string value = parseString(str);
     expect(str, ")");
     drv.env[name] = value;
   }
@@ -195,7 +195,7 @@ Derivation Store::derivationFromPath(const Path& drvPath) {
   }
 }
 
-static void printString(string& res, const string& s) {
+static void printString(std::string& res, const std::string& s) {
   res += '"';
   for (const char* i = s.c_str(); *i != 0; i++) {
     if (*i == '\"' || *i == '\\') {
@@ -215,7 +215,8 @@ static void printString(string& res, const string& s) {
 }
 
 template <class ForwardIterator>
-static void printStrings(string& res, ForwardIterator i, ForwardIterator j) {
+static void printStrings(std::string& res, ForwardIterator i,
+                         ForwardIterator j) {
   res += '[';
   bool first = true;
   for (; i != j; ++i) {
@@ -229,8 +230,8 @@ static void printStrings(string& res, ForwardIterator i, ForwardIterator j) {
   res += ']';
 }
 
-string Derivation::unparse() const {
-  string s;
+std::string Derivation::unparse() const {
+  std::string s;
   s.reserve(65536);
   s += "Derive([";
 
@@ -297,7 +298,7 @@ string Derivation::unparse() const {
   return s;
 }
 
-bool isDerivation(const string& fileName) {
+bool isDerivation(const std::string& fileName) {
   return hasSuffix(fileName, drvExtension);
 }
 
@@ -354,22 +355,23 @@ Hash hashDerivationModulo(Store& store, Derivation drv) {
   return hashString(htSHA256, drv.unparse());
 }
 
-DrvPathWithOutputs parseDrvPathWithOutputs(const string& s) {
+DrvPathWithOutputs parseDrvPathWithOutputs(const std::string& s) {
   size_t n = s.find('!');
   return n == std::string::npos
-             ? DrvPathWithOutputs(s, std::set<string>())
-             : DrvPathWithOutputs(
-                   string(s, 0, n),
-                   tokenizeString<std::set<string> >(string(s, n + 1), ","));
+             ? DrvPathWithOutputs(s, std::set<std::string>())
+             : DrvPathWithOutputs(std::string(s, 0, n),
+                                  tokenizeString<std::set<std::string> >(
+                                      std::string(s, n + 1), ","));
 }
 
 Path makeDrvPathWithOutputs(const Path& drvPath,
-                            const std::set<string>& outputs) {
+                            const std::set<std::string>& outputs) {
   return outputs.empty() ? drvPath
                          : drvPath + "!" + concatStringsSep(",", outputs);
 }
 
-bool wantOutput(const string& output, const std::set<string>& wanted) {
+bool wantOutput(const std::string& output,
+                const std::set<std::string>& wanted) {
   return wanted.empty() || wanted.find(output) != wanted.end();
 }
 
diff --git a/third_party/nix/src/libstore/derivations.hh b/third_party/nix/src/libstore/derivations.hh
index 52b951f5e9..ae365e68bf 100644
--- a/third_party/nix/src/libstore/derivations.hh
+++ b/third_party/nix/src/libstore/derivations.hh
@@ -9,16 +9,16 @@
 namespace nix {
 
 /* Extension of derivations in the Nix store. */
-const string drvExtension = ".drv";
+const std::string drvExtension = ".drv";
 
 /* Abstract syntax of derivations. */
 
 struct DerivationOutput {
   Path path;
-  string hashAlgo; /* hash used for expected hash computation */
-  string hash;     /* expected hash, may be null */
+  std::string hashAlgo; /* hash used for expected hash computation */
+  std::string hash;     /* expected hash, may be null */
   DerivationOutput() {}
-  DerivationOutput(Path path, string hashAlgo, string hash) {
+  DerivationOutput(Path path, std::string hashAlgo, std::string hash) {
     this->path = path;
     this->hashAlgo = hashAlgo;
     this->hash = hash;
@@ -26,18 +26,18 @@ struct DerivationOutput {
   void parseHashInfo(bool& recursive, Hash& hash) const;
 };
 
-typedef std::map<string, DerivationOutput> DerivationOutputs;
+typedef std::map<std::string, DerivationOutput> DerivationOutputs;
 
 /* For inputs that are sub-derivations, we specify exactly which
    output IDs we are interested in. */
 typedef std::map<Path, StringSet> DerivationInputs;
 
-typedef std::map<string, string> StringPairs;
+typedef std::map<std::string, std::string> StringPairs;
 
 struct BasicDerivation {
   DerivationOutputs outputs; /* keyed on symbolic IDs */
   PathSet inputSrcs;         /* inputs that are sources */
-  string platform;
+  std::string platform;
   Path builder;
   Strings args;
   StringPairs env;
@@ -46,7 +46,7 @@ struct BasicDerivation {
 
   /* Return the path corresponding to the output identifier `id' in
      the given derivation. */
-  Path findOutput(const string& id) const;
+  Path findOutput(const std::string& id) const;
 
   bool isBuiltin() const;
 
@@ -68,14 +68,14 @@ class Store;
 
 /* Write a derivation to the Nix store, and return its path. */
 Path writeDerivation(const ref<Store>& store, const Derivation& drv,
-                     const string& name, RepairFlag repair = NoRepair);
+                     const std::string& name, RepairFlag repair = NoRepair);
 
 /* Read a derivation from a file. */
 Derivation readDerivation(const Path& drvPath);
 
 /* Check whether a file name ends with the extension for
    derivations. */
-bool isDerivation(const string& fileName);
+bool isDerivation(const std::string& fileName);
 
 Hash hashDerivationModulo(Store& store, Derivation drv);
 
@@ -87,13 +87,13 @@ extern DrvHashes drvHashes;  // FIXME: global, not thread-safe
 /* Split a string specifying a derivation and a set of outputs
    (/nix/store/hash-foo!out1,out2,...) into the derivation path and
    the outputs. */
-typedef std::pair<string, std::set<string> > DrvPathWithOutputs;
-DrvPathWithOutputs parseDrvPathWithOutputs(const string& s);
+typedef std::pair<std::string, std::set<std::string> > DrvPathWithOutputs;
+DrvPathWithOutputs parseDrvPathWithOutputs(const std::string& s);
 
 Path makeDrvPathWithOutputs(const Path& drvPath,
-                            const std::set<string>& outputs);
+                            const std::set<std::string>& outputs);
 
-bool wantOutput(const string& output, const std::set<string>& wanted);
+bool wantOutput(const std::string& output, const std::set<std::string>& wanted);
 
 struct Source;
 struct Sink;
diff --git a/third_party/nix/src/libstore/download.cc b/third_party/nix/src/libstore/download.cc
index 8767344787..c96caf474c 100644
--- a/third_party/nix/src/libstore/download.cc
+++ b/third_party/nix/src/libstore/download.cc
@@ -177,7 +177,7 @@ struct CurlDownloader : public Downloader {
       DLOG(INFO) << "got header for '" << request.uri << "': " << trim(line);
       if (line.compare(0, 5, "HTTP/") == 0) {  // new response starts
         result.etag = "";
-        auto ss = tokenizeString<vector<string>>(line, " ");
+        auto ss = tokenizeString<std::vector<std::string>>(line, " ");
         status = ss.size() >= 2 ? ss[1] : "";
         result.data = std::make_shared<std::string>();
         result.bodySize = 0;
@@ -185,10 +185,10 @@ struct CurlDownloader : public Downloader {
         encoding = "";
       } else {
         auto i = line.find(':');
-        if (i != string::npos) {
-          string name = toLower(trim(string(line, 0, i)));
+        if (i != std::string::npos) {
+          std::string name = toLower(trim(std::string(line, 0, i)));
           if (name == "etag") {
-            result.etag = trim(string(line, i + 1));
+            result.etag = trim(std::string(line, i + 1));
             /* Hack to work around a GitHub bug: it sends
                ETags, but ignores If-None-Match. So if we get
                the expected ETag on a 200 response, then shut
@@ -200,7 +200,7 @@ struct CurlDownloader : public Downloader {
               return 0;
             }
           } else if (name == "content-encoding") {
-            encoding = trim(string(line, i + 1));
+            encoding = trim(std::string(line, i + 1));
           } else if (name == "accept-ranges" &&
                      toLower(trim(std::string(line, i + 1))) == "bytes") {
             acceptRanges = true;
@@ -868,8 +868,8 @@ CachedDownloadResult Downloader::downloadCached(
   auto name = request.name;
   if (name.empty()) {
     auto p = url.rfind('/');
-    if (p != string::npos) {
-      name = string(url, p + 1);
+    if (p != std::string::npos) {
+      name = std::string(url, p + 1);
     }
   }
 
@@ -888,8 +888,8 @@ CachedDownloadResult Downloader::downloadCached(
   Path cacheDir = getCacheDir() + "/nix/tarballs";
   createDirs(cacheDir);
 
-  string urlHash = hashString(htSHA256, name + std::string("\0"s) + url)
-                       .to_string(Base32, false);
+  std::string urlHash = hashString(htSHA256, name + std::string("\0"s) + url)
+                            .to_string(Base32, false);
 
   Path dataFile = cacheDir + "/" + urlHash + ".info";
   Path fileLink = cacheDir + "/" + urlHash + "-file";
@@ -898,7 +898,7 @@ CachedDownloadResult Downloader::downloadCached(
 
   Path storePath;
 
-  string expectedETag;
+  std::string expectedETag;
 
   bool skip = false;
 
@@ -908,7 +908,8 @@ CachedDownloadResult Downloader::downloadCached(
     storePath = readLink(fileLink);
     store->addTempRoot(storePath);
     if (store->isValidPath(storePath)) {
-      auto ss = tokenizeString<vector<string>>(readFile(dataFile), "\n");
+      auto ss =
+          tokenizeString<std::vector<std::string>>(readFile(dataFile), "\n");
       if (ss.size() >= 3 && ss[0] == url) {
         time_t lastChecked;
         if (string2Int(ss[2], lastChecked) &&
@@ -1009,15 +1010,15 @@ CachedDownloadResult Downloader::downloadCached(
   return result;
 }
 
-bool isUri(const string& s) {
+bool isUri(const std::string& s) {
   if (s.compare(0, 8, "channel:") == 0) {
     return true;
   }
   size_t pos = s.find("://");
-  if (pos == string::npos) {
+  if (pos == std::string::npos) {
     return false;
   }
-  string scheme(s, 0, pos);
+  std::string scheme(s, 0, pos);
   return scheme == "http" || scheme == "https" || scheme == "file" ||
          scheme == "channel" || scheme == "git" || scheme == "s3" ||
          scheme == "ssh";
diff --git a/third_party/nix/src/libstore/download.hh b/third_party/nix/src/libstore/download.hh
index 9ddbdfc159..a988ec6826 100644
--- a/third_party/nix/src/libstore/download.hh
+++ b/third_party/nix/src/libstore/download.hh
@@ -128,6 +128,6 @@ class DownloadError : public Error {
       : Error(fs), error(error) {}
 };
 
-bool isUri(const string& s);
+bool isUri(const std::string& s);
 
 }  // namespace nix
diff --git a/third_party/nix/src/libstore/gc.cc b/third_party/nix/src/libstore/gc.cc
index bc3393265e..1b2364c253 100644
--- a/third_party/nix/src/libstore/gc.cc
+++ b/third_party/nix/src/libstore/gc.cc
@@ -20,8 +20,8 @@
 
 namespace nix {
 
-static string gcLockName = "gc.lock";
-static string gcRootsDir = "gcroots";
+static std::string gcLockName = "gc.lock";
+static std::string gcRootsDir = "gcroots";
 
 /* Acquire the global GC lock.  This is used to prevent new Nix
    processes from starting after the temporary root files have been
@@ -69,7 +69,7 @@ static void makeSymlink(const Path& link, const Path& target) {
 void LocalStore::syncWithGC() { AutoCloseFD fdGCLock = openGCLock(ltRead); }
 
 void LocalStore::addIndirectRoot(const Path& path) {
-  string hash = hashString(htSHA1, path).to_string(Base32, false);
+  std::string hash = hashString(htSHA1, path).to_string(Base32, false);
   Path realRoot = canonPath(
       (format("%1%/%2%/auto/%3%") % stateDir % gcRootsDir % hash).str());
   makeSymlink(realRoot, path);
@@ -105,7 +105,7 @@ Path LocalFSStore::addPermRoot(const Path& _storePath, const Path& _gcRoot,
       Path rootsDir =
           canonPath((format("%1%/%2%") % stateDir % gcRootsDir).str());
 
-      if (string(gcRoot, 0, rootsDir.size() + 1) != rootsDir + "/") {
+      if (std::string(gcRoot, 0, rootsDir.size() + 1) != rootsDir + "/") {
         throw Error(format("path '%1%' is not a valid garbage collector root; "
                            "it's not in the directory '%2%'") %
                     gcRoot % rootsDir);
@@ -184,7 +184,7 @@ void LocalStore::addTempRoot(const Path& path) {
   DLOG(INFO) << "acquiring write lock on " << fnTempRoots;
   lockFile(state->fdTempRoots.get(), ltWrite, true);
 
-  string s = path + '\0';
+  std::string s = path + '\0';
   writeFull(state->fdTempRoots.get(), s);
 
   /* Downgrade to a read lock. */
@@ -233,13 +233,13 @@ void LocalStore::findTempRoots(FDs& fds, Roots& tempRoots, bool censor) {
     lockFile(fd->get(), ltRead, true);
 
     /* Read the entire file. */
-    string contents = readFile(fd->get());
+    std::string contents = readFile(fd->get());
 
     /* Extract the roots. */
-    string::size_type pos = 0;
-    string::size_type end;
+    std::string::size_type pos = 0;
+    std::string::size_type end;
 
-    while ((end = contents.find((char)0, pos)) != string::npos) {
+    while ((end = contents.find((char)0, pos)) != std::string::npos) {
       Path root(contents, pos, end - pos);
       DLOG(INFO) << "got temporary root " << root;
       assertStorePath(root);
@@ -341,7 +341,7 @@ Roots LocalStore::findRoots(bool censor) {
   return roots;
 }
 
-static void readProcLink(const string& file, Roots& roots) {
+static void readProcLink(const std::string& file, Roots& roots) {
   /* 64 is the starting buffer size gnu readlink uses... */
   auto bufsiz = ssize_t{64};
 try_again:
@@ -365,7 +365,7 @@ try_again:
   }
 }
 
-static string quoteRegexChars(const string& raw) {
+static std::string quoteRegexChars(const std::string& raw) {
   static auto specialRegex = std::regex(R"([.^$\\*+?()\[\]{}|])");
   return std::regex_replace(raw, specialRegex, R"(\$&)");
 }
@@ -421,7 +421,7 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
 
         try {
           auto mapFile = fmt("/proc/%s/maps", ent->d_name);
-          auto mapLines = tokenizeString<std::vector<string>>(
+          auto mapLines = tokenizeString<std::vector<std::string>>(
               readFile(mapFile, true), "\n");
           for (const auto& line : mapLines) {
             auto match = std::smatch{};
@@ -458,7 +458,7 @@ void LocalStore::findRuntimeRoots(Roots& roots, bool censor) {
   if (getEnv("_NIX_TEST_NO_LSOF") == "") {
     try {
       std::regex lsofRegex(R"(^n(/.*)$)");
-      auto lsofLines = tokenizeString<std::vector<string>>(
+      auto lsofLines = tokenizeString<std::vector<std::string>>(
           runProgram(LSOF, true, {"-n", "-w", "-F", "n"}), "\n");
       for (const auto& line : lsofLines) {
         std::smatch match;
@@ -511,10 +511,10 @@ struct LocalStore::GCState {
 };
 
 bool LocalStore::isActiveTempFile(const GCState& state, const Path& path,
-                                  const string& suffix) {
+                                  const std::string& suffix) {
   return hasSuffix(path, suffix) &&
-         state.tempRoots.find(string(path, 0, path.size() - suffix.size())) !=
-             state.tempRoots.end();
+         state.tempRoots.find(std::string(
+             path, 0, path.size() - suffix.size())) != state.tempRoots.end();
 }
 
 void LocalStore::deleteGarbage(GCState& state, const Path& path) {
@@ -720,7 +720,7 @@ void LocalStore::removeUnusedLinks(const GCState& state) {
   struct dirent* dirent;
   while (errno = 0, dirent = readdir(dir.get())) {
     checkInterrupt();
-    string name = dirent->d_name;
+    std::string name = dirent->d_name;
     if (name == "." || name == "..") {
       continue;
     }
@@ -863,7 +863,7 @@ void LocalStore::collectGarbage(const GCOptions& options, GCResults& results) {
       struct dirent* dirent;
       while (errno = 0, dirent = readdir(dir.get())) {
         checkInterrupt();
-        string name = dirent->d_name;
+        std::string name = dirent->d_name;
         if (name == "." || name == "..") {
           continue;
         }
@@ -882,7 +882,7 @@ void LocalStore::collectGarbage(const GCOptions& options, GCResults& results) {
          less biased towards deleting paths that come
          alphabetically first (e.g. /nix/store/000...).  This
          matters when using --max-freed etc. */
-      vector<Path> entries_(entries.begin(), entries.end());
+      std::vector<Path> entries_(entries.begin(), entries.end());
       std::mt19937 gen(1);
       std::shuffle(entries_.begin(), entries_.end(), gen);
 
diff --git a/third_party/nix/src/libstore/globals.cc b/third_party/nix/src/libstore/globals.cc
index 856b858368..61293dffed 100644
--- a/third_party/nix/src/libstore/globals.cc
+++ b/third_party/nix/src/libstore/globals.cc
@@ -105,7 +105,7 @@ StringSet Settings::getDefaultSystemFeatures() {
   return features;
 }
 
-const string nixVersion = PACKAGE_VERSION;
+const std::string nixVersion = PACKAGE_VERSION;
 
 template <>
 void BaseSetting<SandboxMode>::set(const std::string& str) {
diff --git a/third_party/nix/src/libstore/globals.hh b/third_party/nix/src/libstore/globals.hh
index 71bc2b1e74..feff548790 100644
--- a/third_party/nix/src/libstore/globals.hh
+++ b/third_party/nix/src/libstore/globals.hh
@@ -468,6 +468,6 @@ void initPlugins();
 
 void loadConfFile();
 
-extern const string nixVersion;
+extern const std::string nixVersion;
 
 }  // namespace nix
diff --git a/third_party/nix/src/libstore/http-binary-cache-store.cc b/third_party/nix/src/libstore/http-binary-cache-store.cc
index 1a46423b35..c75d5f2860 100644
--- a/third_party/nix/src/libstore/http-binary-cache-store.cc
+++ b/third_party/nix/src/libstore/http-binary-cache-store.cc
@@ -94,7 +94,7 @@ class HttpBinaryCacheStore : public BinaryCacheStore {
   void upsertFile(const std::string& path, const std::string& data,
                   const std::string& mimeType) override {
     auto req = DownloadRequest(cacheUri + "/" + path);
-    req.data = std::make_shared<string>(data);  // FIXME: inefficient
+    req.data = std::make_shared<std::string>(data);  // FIXME: inefficient
     req.mimeType = mimeType;
     try {
       getDownloader()->download(req);
diff --git a/third_party/nix/src/libstore/legacy-ssh-store.cc b/third_party/nix/src/libstore/legacy-ssh-store.cc
index 9a84e02956..9e6870f0da 100644
--- a/third_party/nix/src/libstore/legacy-ssh-store.cc
+++ b/third_party/nix/src/libstore/legacy-ssh-store.cc
@@ -43,7 +43,7 @@ struct LegacySSHStore : public Store {
 
   SSHMaster master;
 
-  LegacySSHStore(const string& host, const Params& params)
+  LegacySSHStore(const std::string& host, const Params& params)
       : Store(params),
         host(host),
         connections(make_ref<Pool<Connection>>(
@@ -85,7 +85,7 @@ struct LegacySSHStore : public Store {
     return conn;
   };
 
-  string getUri() override { return uriScheme + host; }
+  std::string getUri() override { return uriScheme + host; }
 
   void queryPathInfoUncached(
       const Path& path,
@@ -176,17 +176,17 @@ struct LegacySSHStore : public Store {
     copyNAR(conn->from, sink);
   }
 
-  Path queryPathFromHashPart(const string& hashPart) override {
+  Path queryPathFromHashPart(const std::string& hashPart) override {
     unsupported("queryPathFromHashPart");
   }
 
-  Path addToStore(const string& name, const Path& srcPath, bool recursive,
+  Path addToStore(const std::string& name, const Path& srcPath, bool recursive,
                   HashType hashAlgo, PathFilter& filter,
                   RepairFlag repair) override {
     unsupported("addToStore");
   }
 
-  Path addTextToStore(const string& name, const string& s,
+  Path addTextToStore(const std::string& name, const std::string& s,
                       const PathSet& references, RepairFlag repair) override {
     unsupported("addTextToStore");
   }
diff --git a/third_party/nix/src/libstore/local-fs-store.cc b/third_party/nix/src/libstore/local-fs-store.cc
index 2120afc0ce..f11c84b182 100644
--- a/third_party/nix/src/libstore/local-fs-store.cc
+++ b/third_party/nix/src/libstore/local-fs-store.cc
@@ -79,7 +79,7 @@ void LocalFSStore::narFromPath(const Path& path, Sink& sink) {
   dumpPath(getRealStoreDir() + std::string(path, storeDir.size()), sink);
 }
 
-const string LocalFSStore::drvsLogDir = "drvs";
+const std::string LocalFSStore::drvsLogDir = "drvs";
 
 std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path& path_) {
   auto path(path_);
@@ -97,12 +97,13 @@ std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path& path_) {
     }
   }
 
-  string baseName = baseNameOf(path);
+  std::string baseName = baseNameOf(path);
 
   for (int j = 0; j < 2; j++) {
-    Path logPath = j == 0 ? fmt("%s/%s/%s/%s", logDir, drvsLogDir,
-                                string(baseName, 0, 2), string(baseName, 2))
-                          : fmt("%s/%s/%s", logDir, drvsLogDir, baseName);
+    Path logPath =
+        j == 0 ? fmt("%s/%s/%s/%s", logDir, drvsLogDir,
+                     std::string(baseName, 0, 2), std::string(baseName, 2))
+               : fmt("%s/%s/%s", logDir, drvsLogDir, baseName);
     Path logBz2Path = logPath + ".bz2";
 
     if (pathExists(logPath)) {
diff --git a/third_party/nix/src/libstore/local-store.cc b/third_party/nix/src/libstore/local-store.cc
index a89c6a7975..84055740de 100644
--- a/third_party/nix/src/libstore/local-store.cc
+++ b/third_party/nix/src/libstore/local-store.cc
@@ -10,10 +10,16 @@
 #include <fcntl.h>
 #include <glog/logging.h>
 #include <grp.h>
+#include <sched.h>
+#include <sqlite3.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
 #include <sys/select.h>
 #include <sys/stat.h>
+#include <sys/statvfs.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/xattr.h>
 #include <unistd.h>
 #include <utime.h>
 
@@ -24,13 +30,6 @@
 #include "pathlocks.hh"
 #include "worker-protocol.hh"
 
-#include <sched.h>
-#include <sys/ioctl.h>
-#include <sys/mount.h>
-#include <sys/statvfs.h>
-#include <sys/xattr.h>
-#include <sqlite3.h>
-
 namespace nix {
 
 LocalStore::LocalStore(const Params& params)
@@ -136,7 +135,7 @@ LocalStore::LocalStore(const Params& params)
       res = posix_fallocate(fd.get(), 0, settings.reservedSize);
 #endif
       if (res == -1) {
-        writeFull(fd.get(), string(settings.reservedSize, 'X'));
+        writeFull(fd.get(), std::string(settings.reservedSize, 'X'));
         [[gnu::unused]] auto res2 = ftruncate(fd.get(), settings.reservedSize);
       }
     }
@@ -295,7 +294,7 @@ std::string LocalStore::getUri() { return "local"; }
 int LocalStore::getSchema() {
   int curSchema = 0;
   if (pathExists(schemaPath)) {
-    string s = readFile(schemaPath);
+    std::string s = readFile(schemaPath);
     if (!string2Int(s, curSchema)) {
       throw Error(format("'%1%' is corrupt") % schemaPath);
     }
@@ -310,7 +309,7 @@ void LocalStore::openDB(State& state, bool create) {
   }
 
   /* Open the Nix database. */
-  string dbPath = dbDir + "/db.sqlite";
+  std::string dbPath = dbDir + "/db.sqlite";
   auto& db(state.db);
   if (sqlite3_open_v2(dbPath.c_str(), &db.db,
                       SQLITE_OPEN_READWRITE | (create ? SQLITE_OPEN_CREATE : 0),
@@ -341,20 +340,20 @@ void LocalStore::openDB(State& state, bool create) {
      should be safe enough.  If the user asks for it, don't sync at
      all.  This can cause database corruption if the system
      crashes. */
-  string syncMode = settings.fsyncMetadata ? "normal" : "off";
+  std::string syncMode = settings.fsyncMetadata ? "normal" : "off";
   db.exec("pragma synchronous = " + syncMode);
 
   /* Set the SQLite journal mode.  WAL mode is fastest, so it's the
      default. */
-  string mode = settings.useSQLiteWAL ? "wal" : "truncate";
-  string prevMode;
+  std::string mode = settings.useSQLiteWAL ? "wal" : "truncate";
+  std::string prevMode;
   {
     SQLiteStmt stmt;
     stmt.create(db, "pragma main.journal_mode;");
     if (sqlite3_step(stmt) != SQLITE_ROW) {
       throwSQLiteError(db, "querying journal mode");
     }
-    prevMode = string((const char*)sqlite3_column_text(stmt, 0));
+    prevMode = std::string((const char*)sqlite3_column_text(stmt, 0));
   }
   if (prevMode != mode &&
       sqlite3_exec(db, ("pragma main.journal_mode = " + mode + ";").c_str(),
@@ -563,9 +562,9 @@ void canonicalisePathMetaData(const Path& path, uid_t fromUid) {
 
 void LocalStore::checkDerivationOutputs(const Path& drvPath,
                                         const Derivation& drv) {
-  string drvName = storePathToName(drvPath);
+  std::string drvName = storePathToName(drvPath);
   assert(isDerivation(drvName));
-  drvName = string(drvName, 0, drvName.size() - drvExtension.size());
+  drvName = std::string(drvName, 0, drvName.size() - drvExtension.size());
 
   if (drv.isFixedOutput()) {
     auto out = drv.outputs.find("out");
@@ -843,7 +842,7 @@ StringSet LocalStore::queryDerivationOutputNames(const Path& path) {
   });
 }
 
-Path LocalStore::queryPathFromHashPart(const string& hashPart) {
+Path LocalStore::queryPathFromHashPart(const std::string& hashPart) {
   if (hashPart.size() != storePathHashLen) {
     throw Error("invalid hash part");
   }
@@ -1096,9 +1095,9 @@ void LocalStore::addToStore(const ValidPathInfo& info, Source& source,
   }
 }
 
-Path LocalStore::addToStoreFromDump(const string& dump, const string& name,
-                                    bool recursive, HashType hashAlgo,
-                                    RepairFlag repair) {
+Path LocalStore::addToStoreFromDump(const std::string& dump,
+                                    const std::string& name, bool recursive,
+                                    HashType hashAlgo, RepairFlag repair) {
   Hash h = hashString(hashAlgo, dump);
 
   Path dstPath = makeFixedOutputPath(recursive, h, name);
@@ -1155,7 +1154,7 @@ Path LocalStore::addToStoreFromDump(const string& dump, const string& name,
   return dstPath;
 }
 
-Path LocalStore::addToStore(const string& name, const Path& _srcPath,
+Path LocalStore::addToStore(const std::string& name, const Path& _srcPath,
                             bool recursive, HashType hashAlgo,
                             PathFilter& filter, RepairFlag repair) {
   Path srcPath(absPath(_srcPath));
@@ -1173,7 +1172,7 @@ Path LocalStore::addToStore(const string& name, const Path& _srcPath,
   return addToStoreFromDump(*sink.s, name, recursive, hashAlgo, repair);
 }
 
-Path LocalStore::addTextToStore(const string& name, const string& s,
+Path LocalStore::addTextToStore(const std::string& name, const std::string& s,
                                 const PathSet& references, RepairFlag repair) {
   auto hash = hashString(htSHA256, s);
   auto dstPath = makeTextPath(name, hash, references);
diff --git a/third_party/nix/src/libstore/local-store.hh b/third_party/nix/src/libstore/local-store.hh
index 1a58df8161..c1bfc08764 100644
--- a/third_party/nix/src/libstore/local-store.hh
+++ b/third_party/nix/src/libstore/local-store.hh
@@ -125,7 +125,7 @@ class LocalStore : public LocalFSStore {
 
   StringSet queryDerivationOutputNames(const Path& path) override;
 
-  Path queryPathFromHashPart(const string& hashPart) override;
+  Path queryPathFromHashPart(const std::string& hashPart) override;
 
   PathSet querySubstitutablePaths(const PathSet& paths) override;
 
@@ -136,7 +136,7 @@ class LocalStore : public LocalFSStore {
                   CheckSigsFlag checkSigs,
                   std::shared_ptr<FSAccessor> accessor) override;
 
-  Path addToStore(const string& name, const Path& srcPath, bool recursive,
+  Path addToStore(const std::string& name, const Path& srcPath, bool recursive,
                   HashType hashAlgo, PathFilter& filter,
                   RepairFlag repair) override;
 
@@ -144,11 +144,11 @@ class LocalStore : public LocalFSStore {
      in `dump', which is either a NAR serialisation (if recursive ==
      true) or simply the contents of a regular file (if recursive ==
      false). */
-  Path addToStoreFromDump(const string& dump, const string& name,
+  Path addToStoreFromDump(const std::string& dump, const std::string& name,
                           bool recursive = true, HashType hashAlgo = htSHA256,
                           RepairFlag repair = NoRepair);
 
-  Path addTextToStore(const string& name, const string& s,
+  Path addTextToStore(const std::string& name, const std::string& s,
                       const PathSet& references, RepairFlag repair) override;
 
   void buildPaths(const PathSet& paths, BuildMode buildMode) override;
@@ -166,7 +166,7 @@ class LocalStore : public LocalFSStore {
 
  private:
   typedef std::shared_ptr<AutoCloseFD> FDPtr;
-  typedef list<FDPtr> FDs;
+  typedef std::list<FDPtr> FDs;
 
   void findTempRoots(FDs& fds, Roots& roots, bool censor);
 
@@ -248,7 +248,7 @@ class LocalStore : public LocalFSStore {
   void deletePathRecursive(GCState& state, const Path& path);
 
   static bool isActiveTempFile(const GCState& state, const Path& path,
-                               const string& suffix);
+                               const std::string& suffix);
 
   AutoCloseFD openGCLock(LockType lockType);
 
@@ -290,7 +290,7 @@ class LocalStore : public LocalFSStore {
 };
 
 typedef std::pair<dev_t, ino_t> Inode;
-typedef set<Inode> InodesSeen;
+typedef std::set<Inode> InodesSeen;
 
 /* "Fix", or canonicalise, the meta-data of the files in a store path
    after it has been built.  In particular:
diff --git a/third_party/nix/src/libstore/machines.cc b/third_party/nix/src/libstore/machines.cc
index 5b0c7e72dd..2f1a7289bd 100644
--- a/third_party/nix/src/libstore/machines.cc
+++ b/third_party/nix/src/libstore/machines.cc
@@ -32,22 +32,22 @@ Machine::Machine(decltype(storeUri)& storeUri,
       mandatoryFeatures(mandatoryFeatures),
       sshPublicHostKey(sshPublicHostKey) {}
 
-bool Machine::allSupported(const std::set<string>& features) const {
+bool Machine::allSupported(const std::set<std::string>& features) const {
   return std::all_of(features.begin(), features.end(),
-                     [&](const string& feature) {
+                     [&](const std::string& feature) {
                        return (supportedFeatures.count(feature) != 0u) ||
                               (mandatoryFeatures.count(feature) != 0u);
                      });
 }
 
-bool Machine::mandatoryMet(const std::set<string>& features) const {
+bool Machine::mandatoryMet(const std::set<std::string>& features) const {
   return std::all_of(
       mandatoryFeatures.begin(), mandatoryFeatures.end(),
-      [&](const string& feature) { return features.count(feature); });
+      [&](const std::string& feature) { return features.count(feature); });
 }
 
 void parseMachines(const std::string& s, Machines& machines) {
-  for (auto line : tokenizeString<std::vector<string>>(s, "\n;")) {
+  for (auto line : tokenizeString<std::vector<std::string>>(s, "\n;")) {
     trim(line);
     line.erase(std::find(line.begin(), line.end(), '#'), line.end());
     if (line.empty()) {
@@ -67,7 +67,7 @@ void parseMachines(const std::string& s, Machines& machines) {
       continue;
     }
 
-    auto tokens = tokenizeString<std::vector<string>>(line);
+    auto tokens = tokenizeString<std::vector<std::string>>(line);
     auto sz = tokens.size();
     if (sz < 1) {
       throw FormatError("bad machine specification '%s'", line);
@@ -79,14 +79,14 @@ void parseMachines(const std::string& s, Machines& machines) {
 
     machines.emplace_back(
         tokens[0],
-        isSet(1) ? tokenizeString<std::vector<string>>(tokens[1], ",")
-                 : std::vector<string>{settings.thisSystem},
+        isSet(1) ? tokenizeString<std::vector<std::string>>(tokens[1], ",")
+                 : std::vector<std::string>{settings.thisSystem},
         isSet(2) ? tokens[2] : "", isSet(3) ? std::stoull(tokens[3]) : 1LL,
         isSet(4) ? std::stoull(tokens[4]) : 1LL,
-        isSet(5) ? tokenizeString<std::set<string>>(tokens[5], ",")
-                 : std::set<string>{},
-        isSet(6) ? tokenizeString<std::set<string>>(tokens[6], ",")
-                 : std::set<string>{},
+        isSet(5) ? tokenizeString<std::set<std::string>>(tokens[5], ",")
+                 : std::set<std::string>{},
+        isSet(6) ? tokenizeString<std::set<std::string>>(tokens[6], ",")
+                 : std::set<std::string>{},
         isSet(7) ? tokens[7] : "");
   }
 }
diff --git a/third_party/nix/src/libstore/machines.hh b/third_party/nix/src/libstore/machines.hh
index aef8054c25..23712e6760 100644
--- a/third_party/nix/src/libstore/machines.hh
+++ b/third_party/nix/src/libstore/machines.hh
@@ -5,19 +5,19 @@
 namespace nix {
 
 struct Machine {
-  const string storeUri;
-  const std::vector<string> systemTypes;
-  const string sshKey;
+  const std::string storeUri;
+  const std::vector<std::string> systemTypes;
+  const std::string sshKey;
   const unsigned int maxJobs;
   const unsigned int speedFactor;
-  const std::set<string> supportedFeatures;
-  const std::set<string> mandatoryFeatures;
+  const std::set<std::string> supportedFeatures;
+  const std::set<std::string> mandatoryFeatures;
   const std::string sshPublicHostKey;
   bool enabled = true;
 
-  bool allSupported(const std::set<string>& features) const;
+  bool allSupported(const std::set<std::string>& features) const;
 
-  bool mandatoryMet(const std::set<string>& features) const;
+  bool mandatoryMet(const std::set<std::string>& features) const;
 
   Machine(decltype(storeUri)& storeUri, decltype(systemTypes)& systemTypes,
           decltype(sshKey)& sshKey, decltype(maxJobs) maxJobs,
diff --git a/third_party/nix/src/libstore/nar-accessor.cc b/third_party/nix/src/libstore/nar-accessor.cc
index 7f6e0377ae..84bfb531ec 100644
--- a/third_party/nix/src/libstore/nar-accessor.cc
+++ b/third_party/nix/src/libstore/nar-accessor.cc
@@ -74,7 +74,7 @@ struct NarAccessor : public FSAccessor {
     void isExecutable() override { parents.top()->isExecutable = true; }
 
     void preallocateContents(unsigned long long size) override {
-      currentStart = string(s, pos, 16);
+      currentStart = std::string(s, pos, 16);
       assert(size <= std::numeric_limits<size_t>::max());
       parents.top()->size = (size_t)size;
       parents.top()->start = pos;
@@ -83,12 +83,12 @@ struct NarAccessor : public FSAccessor {
     void receiveContents(unsigned char* data, unsigned int len) override {
       // Sanity check
       if (!currentStart.empty()) {
-        assert(len < 16 || currentStart == string((char*)data, 16));
+        assert(len < 16 || currentStart == std::string((char*)data, 16));
         currentStart.clear();
       }
     }
 
-    void createSymlink(const Path& path, const string& target) override {
+    void createSymlink(const Path& path, const std::string& target) override {
       createMember(path,
                    NarMember{FSAccessor::Type::tSymlink, false, 0, 0, target});
     }
diff --git a/third_party/nix/src/libstore/nar-info.cc b/third_party/nix/src/libstore/nar-info.cc
index 91cf471554..5a217d1b61 100644
--- a/third_party/nix/src/libstore/nar-info.cc
+++ b/third_party/nix/src/libstore/nar-info.cc
@@ -10,7 +10,7 @@ NarInfo::NarInfo(const Store& store, const std::string& s,
     throw Error(format("NAR info file '%1%' is corrupt") % whence);
   };
 
-  auto parseHashField = [&](const string& s) {
+  auto parseHashField = [&](const std::string& s) {
     try {
       return Hash(s);
     } catch (BadHash&) {
diff --git a/third_party/nix/src/libstore/optimise-store.cc b/third_party/nix/src/libstore/optimise-store.cc
index caeff72363..7217d54ca9 100644
--- a/third_party/nix/src/libstore/optimise-store.cc
+++ b/third_party/nix/src/libstore/optimise-store.cc
@@ -83,7 +83,7 @@ Strings LocalStore::readDirectoryIgnoringInodes(const Path& path,
       continue;
     }
 
-    string name = dirent->d_name;
+    std::string name = dirent->d_name;
     if (name == "." || name == "..") {
       continue;
     }
@@ -271,7 +271,7 @@ void LocalStore::optimiseStore(OptimiseStats& stats) {
   }
 }
 
-static string showBytes(unsigned long long bytes) {
+static std::string showBytes(unsigned long long bytes) {
   return (format("%.2f MiB") % (bytes / (1024.0 * 1024.0))).str();
 }
 
diff --git a/third_party/nix/src/libstore/pathlocks.cc b/third_party/nix/src/libstore/pathlocks.cc
index eeee5ee1e9..642e64a62b 100644
--- a/third_party/nix/src/libstore/pathlocks.cc
+++ b/third_party/nix/src/libstore/pathlocks.cc
@@ -73,12 +73,12 @@ bool lockFile(int fd, LockType lockType, bool wait) {
 
 PathLocks::PathLocks() : deletePaths(false) {}
 
-PathLocks::PathLocks(const PathSet& paths, const string& waitMsg)
+PathLocks::PathLocks(const PathSet& paths, const std::string& waitMsg)
     : deletePaths(false) {
   lockPaths(paths, waitMsg);
 }
 
-bool PathLocks::lockPaths(const PathSet& paths, const string& waitMsg,
+bool PathLocks::lockPaths(const PathSet& paths, const std::string& waitMsg,
                           bool wait) {
   assert(fds.empty());
 
diff --git a/third_party/nix/src/libstore/pathlocks.hh b/third_party/nix/src/libstore/pathlocks.hh
index 90184989cd..201e3f01b4 100644
--- a/third_party/nix/src/libstore/pathlocks.hh
+++ b/third_party/nix/src/libstore/pathlocks.hh
@@ -19,13 +19,13 @@ bool lockFile(int fd, LockType lockType, bool wait);
 class PathLocks {
  private:
   typedef std::pair<int, Path> FDPair;
-  list<FDPair> fds;
+  std::list<FDPair> fds;
   bool deletePaths;
 
  public:
   PathLocks();
-  PathLocks(const PathSet& paths, const string& waitMsg = "");
-  bool lockPaths(const PathSet& _paths, const string& waitMsg = "",
+  PathLocks(const PathSet& paths, const std::string& waitMsg = "");
+  bool lockPaths(const PathSet& _paths, const std::string& waitMsg = "",
                  bool wait = true);
   ~PathLocks();
   void unlock();
diff --git a/third_party/nix/src/libstore/profiles.cc b/third_party/nix/src/libstore/profiles.cc
index bdb90b7388..7c802d7549 100644
--- a/third_party/nix/src/libstore/profiles.cc
+++ b/third_party/nix/src/libstore/profiles.cc
@@ -19,17 +19,17 @@ static bool cmpGensByNumber(const Generation& a, const Generation& b) {
 
 /* Parse a generation name of the format
    `<profilename>-<number>-link'. */
-static int parseName(const string& profileName, const string& name) {
-  if (string(name, 0, profileName.size() + 1) != profileName + "-") {
+static int parseName(const std::string& profileName, const std::string& name) {
+  if (std::string(name, 0, profileName.size() + 1) != profileName + "-") {
     return -1;
   }
-  string s = string(name, profileName.size() + 1);
-  string::size_type p = s.find("-link");
-  if (p == string::npos) {
+  std::string s = std::string(name, profileName.size() + 1);
+  std::string::size_type p = s.find("-link");
+  if (p == std::string::npos) {
     return -1;
   }
   int n;
-  if (string2Int(string(s, 0, p), n) && n >= 0) {
+  if (string2Int(std::string(s, 0, p), n) && n >= 0) {
     return n;
   }
   return -1;
@@ -39,7 +39,7 @@ Generations findGenerations(const Path& profile, int& curGen) {
   Generations gens;
 
   Path profileDir = dirOf(profile);
-  string profileName = baseNameOf(profile);
+  std::string profileName = baseNameOf(profile);
 
   for (auto& i : readDirectory(profileDir)) {
     int n;
@@ -212,10 +212,10 @@ void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun) {
   }
 }
 
-void deleteGenerationsOlderThan(const Path& profile, const string& timeSpec,
-                                bool dryRun) {
+void deleteGenerationsOlderThan(const Path& profile,
+                                const std::string& timeSpec, bool dryRun) {
   time_t curTime = time(nullptr);
-  string strDays = string(timeSpec, 0, timeSpec.size() - 1);
+  std::string strDays = std::string(timeSpec, 0, timeSpec.size() - 1);
   int days;
 
   if (!string2Int(strDays, days) || days < 1) {
@@ -242,7 +242,7 @@ void lockProfile(PathLocks& lock, const Path& profile) {
   lock.setDeletion(true);
 }
 
-string optimisticLockProfile(const Path& profile) {
+std::string optimisticLockProfile(const Path& profile) {
   return pathExists(profile) ? readLink(profile) : "";
 }
 
diff --git a/third_party/nix/src/libstore/profiles.hh b/third_party/nix/src/libstore/profiles.hh
index ab31cc993a..9f31083b32 100644
--- a/third_party/nix/src/libstore/profiles.hh
+++ b/third_party/nix/src/libstore/profiles.hh
@@ -15,7 +15,7 @@ struct Generation {
   operator bool() const { return number != -1; }
 };
 
-typedef list<Generation> Generations;
+typedef std::list<Generation> Generations;
 
 /* Returns the list of currently present generations for the specified
    profile, sorted by generation number. */
@@ -38,8 +38,8 @@ void deleteOldGenerations(const Path& profile, bool dryRun);
 
 void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun);
 
-void deleteGenerationsOlderThan(const Path& profile, const string& timeSpec,
-                                bool dryRun);
+void deleteGenerationsOlderThan(const Path& profile,
+                                const std::string& timeSpec, bool dryRun);
 
 void switchLink(const Path& link, Path target);
 
@@ -56,6 +56,6 @@ void lockProfile(PathLocks& lock, const Path& profile);
    generally cheap, since the build results are still in the Nix
    store.  Most of the time, only the user environment has to be
    rebuilt. */
-string optimisticLockProfile(const Path& profile);
+std::string optimisticLockProfile(const Path& profile);
 
 }  // namespace nix
diff --git a/third_party/nix/src/libstore/references.cc b/third_party/nix/src/libstore/references.cc
index c8cebaec08..6b9b7137c4 100644
--- a/third_party/nix/src/libstore/references.cc
+++ b/third_party/nix/src/libstore/references.cc
@@ -40,7 +40,7 @@ static void search(const unsigned char* s, size_t len, StringSet& hashes,
     if (!match) {
       continue;
     }
-    string ref((const char*)s + i, refLength);
+    std::string ref((const char*)s + i, refLength);
     if (hashes.find(ref) != hashes.end()) {
       DLOG(INFO) << "found reference to '" << ref << "' at offset " << i;
       seen.insert(ref);
@@ -55,7 +55,7 @@ struct RefScanSink : Sink {
   StringSet hashes;
   StringSet seen;
 
-  string tail;
+  std::string tail;
 
   RefScanSink() : hashSink(htSHA256) {}
 
@@ -68,34 +68,34 @@ void RefScanSink::operator()(const unsigned char* data, size_t len) {
   /* It's possible that a reference spans the previous and current
      fragment, so search in the concatenation of the tail of the
      previous fragment and the start of the current fragment. */
-  string s =
-      tail + string((const char*)data, len > refLength ? refLength : len);
+  std::string s =
+      tail + std::string((const char*)data, len > refLength ? refLength : len);
   search((const unsigned char*)s.data(), s.size(), hashes, seen);
 
   search(data, len, hashes, seen);
 
   size_t tailLen = len <= refLength ? len : refLength;
-  tail = string(tail, tail.size() < refLength - tailLen
-                          ? 0
-                          : tail.size() - (refLength - tailLen)) +
-         string((const char*)data + len - tailLen, tailLen);
+  tail = std::string(tail, tail.size() < refLength - tailLen
+                               ? 0
+                               : tail.size() - (refLength - tailLen)) +
+         std::string((const char*)data + len - tailLen, tailLen);
 }
 
-PathSet scanForReferences(const string& path, const PathSet& refs,
+PathSet scanForReferences(const std::string& path, const PathSet& refs,
                           HashResult& hash) {
   RefScanSink sink;
-  std::map<string, Path> backMap;
+  std::map<std::string, Path> backMap;
 
   /* For efficiency (and a higher hit rate), just search for the
      hash part of the file name.  (This assumes that all references
      have the form `HASH-bla'). */
   for (auto& i : refs) {
-    string baseName = baseNameOf(i);
-    string::size_type pos = baseName.find('-');
-    if (pos == string::npos) {
+    std::string baseName = baseNameOf(i);
+    std::string::size_type pos = baseName.find('-');
+    if (pos == std::string::npos) {
       throw Error(format("bad reference '%1%'") % i);
     }
-    string s = string(baseName, 0, pos);
+    std::string s = std::string(baseName, 0, pos);
     assert(s.size() == refLength);
     assert(backMap.find(s) == backMap.end());
     // parseHash(htSHA256, s);
@@ -109,7 +109,7 @@ PathSet scanForReferences(const string& path, const PathSet& refs,
   /* Map the hashes found back to their store paths. */
   PathSet found;
   for (auto& i : sink.seen) {
-    std::map<string, Path>::iterator j;
+    std::map<std::string, Path>::iterator j;
     if ((j = backMap.find(i)) == backMap.end()) {
       abort();
     }
diff --git a/third_party/nix/src/libstore/remote-store.cc b/third_party/nix/src/libstore/remote-store.cc
index cc6f6ebae9..c5d1dac6cb 100644
--- a/third_party/nix/src/libstore/remote-store.cc
+++ b/third_party/nix/src/libstore/remote-store.cc
@@ -102,7 +102,7 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection() {
   }
   closeOnExec(conn->fd.get());
 
-  string socketPath = path ? *path : settings.nixDaemonSocketFile;
+  std::string socketPath = path ? *path : settings.nixDaemonSocketFile;
 
   struct sockaddr_un addr;
   addr.sun_family = AF_UNIX;
@@ -412,7 +412,7 @@ PathSet RemoteStore::queryDerivationOutputNames(const Path& path) {
   return readStrings<PathSet>(conn->from);
 }
 
-Path RemoteStore::queryPathFromHashPart(const string& hashPart) {
+Path RemoteStore::queryPathFromHashPart(const std::string& hashPart) {
   auto conn(getConnection());
   conn->to << wopQueryPathFromHashPart << hashPart;
   conn.processStderr();
@@ -460,7 +460,7 @@ void RemoteStore::addToStore(const ValidPathInfo& info, Source& source,
   }
 }
 
-Path RemoteStore::addToStore(const string& name, const Path& _srcPath,
+Path RemoteStore::addToStore(const std::string& name, const Path& _srcPath,
                              bool recursive, HashType hashAlgo,
                              PathFilter& filter, RepairFlag repair) {
   if (repair != 0u) {
@@ -503,7 +503,7 @@ Path RemoteStore::addToStore(const string& name, const Path& _srcPath,
   return readStorePath(*this, conn->from);
 }
 
-Path RemoteStore::addTextToStore(const string& name, const string& s,
+Path RemoteStore::addTextToStore(const std::string& name, const std::string& s,
                                  const PathSet& references, RepairFlag repair) {
   if (repair != 0u) {
     throw Error(
@@ -537,7 +537,7 @@ void RemoteStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
        identifiers. */
     PathSet drvPaths2;
     for (auto& i : drvPaths) {
-      drvPaths2.insert(string(i, 0, i.find('!')));
+      drvPaths2.insert(std::string(i, 0, i.find('!')));
     }
     conn->to << drvPaths2;
   }
@@ -692,7 +692,7 @@ std::exception_ptr RemoteStore::Connection::processStderr(Sink* sink,
     auto msg = readNum<uint64_t>(from);
 
     if (msg == STDERR_WRITE) {
-      string s = readString(from);
+      std::string s = readString(from);
       if (sink == nullptr) {
         throw Error("no sink");
       }
@@ -710,7 +710,7 @@ std::exception_ptr RemoteStore::Connection::processStderr(Sink* sink,
     }
 
     else if (msg == STDERR_ERROR) {
-      string error = readString(from);
+      std::string error = readString(from);
       unsigned int status = readInt(from);
       return std::make_exception_ptr(Error(status, error));
     }
diff --git a/third_party/nix/src/libstore/remote-store.hh b/third_party/nix/src/libstore/remote-store.hh
index dc44cd32ac..e61e72892c 100644
--- a/third_party/nix/src/libstore/remote-store.hh
+++ b/third_party/nix/src/libstore/remote-store.hh
@@ -52,7 +52,7 @@ class RemoteStore : public virtual Store {
 
   StringSet queryDerivationOutputNames(const Path& path) override;
 
-  Path queryPathFromHashPart(const string& hashPart) override;
+  Path queryPathFromHashPart(const std::string& hashPart) override;
 
   PathSet querySubstitutablePaths(const PathSet& paths) override;
 
@@ -63,12 +63,12 @@ class RemoteStore : public virtual Store {
                   CheckSigsFlag checkSigs,
                   std::shared_ptr<FSAccessor> accessor) override;
 
-  Path addToStore(const string& name, const Path& srcPath,
+  Path addToStore(const std::string& name, const Path& srcPath,
                   bool recursive = true, HashType hashAlgo = htSHA256,
                   PathFilter& filter = defaultPathFilter,
                   RepairFlag repair = NoRepair) override;
 
-  Path addTextToStore(const string& name, const string& s,
+  Path addTextToStore(const std::string& name, const std::string& s,
                       const PathSet& references, RepairFlag repair) override;
 
   void buildPaths(const PathSet& paths, BuildMode buildMode) override;
diff --git a/third_party/nix/src/libstore/s3-binary-cache-store.cc b/third_party/nix/src/libstore/s3-binary-cache-store.cc
index df3afab3cf..2b25fd8744 100644
--- a/third_party/nix/src/libstore/s3-binary-cache-store.cc
+++ b/third_party/nix/src/libstore/s3-binary-cache-store.cc
@@ -77,8 +77,8 @@ static void initAWS() {
   });
 }
 
-S3Helper::S3Helper(const string& profile, const string& region,
-                   const string& scheme, const string& endpoint)
+S3Helper::S3Helper(const std::string& profile, const std::string& region,
+                   const std::string& scheme, const std::string& endpoint)
     : config(makeConfig(region, scheme, endpoint)),
       client(make_ref<Aws::S3::S3Client>(
           profile == ""
@@ -114,7 +114,8 @@ class RetryStrategy : public Aws::Client::DefaultRetryStrategy {
 };
 
 ref<Aws::Client::ClientConfiguration> S3Helper::makeConfig(
-    const string& region, const string& scheme, const string& endpoint) {
+    const std::string& region, const std::string& scheme,
+    const std::string& endpoint) {
   initAWS();
   auto res = make_ref<Aws::Client::ClientConfiguration>();
   res->region = region;
diff --git a/third_party/nix/src/libstore/sqlite.cc b/third_party/nix/src/libstore/sqlite.cc
index 2dea952d02..dbdaa29d4f 100644
--- a/third_party/nix/src/libstore/sqlite.cc
+++ b/third_party/nix/src/libstore/sqlite.cc
@@ -54,7 +54,7 @@ void SQLite::exec(const std::string& stmt) {
   });
 }
 
-void SQLiteStmt::create(sqlite3* db, const string& sql) {
+void SQLiteStmt::create(sqlite3* db, const std::string& sql) {
   checkInterrupt();
   assert(!stmt);
   if (sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr) != SQLITE_OK) {
diff --git a/third_party/nix/src/libstore/store-api.cc b/third_party/nix/src/libstore/store-api.cc
index 50e9b3b6ea..e6891395cd 100644
--- a/third_party/nix/src/libstore/store-api.cc
+++ b/third_party/nix/src/libstore/store-api.cc
@@ -48,7 +48,7 @@ Path Store::followLinksToStore(const Path& _path) const {
     if (!isLink(path)) {
       break;
     }
-    string target = readLink(path);
+    std::string target = readLink(path);
     path = absPath(target, dirOf(path));
   }
   if (!isInStore(path)) {
@@ -61,22 +61,23 @@ Path Store::followLinksToStorePath(const Path& path) const {
   return toStorePath(followLinksToStore(path));
 }
 
-string storePathToName(const Path& path) {
+std::string storePathToName(const Path& path) {
   auto base = baseNameOf(path);
   assert(base.size() == storePathHashLen ||
          (base.size() > storePathHashLen && base[storePathHashLen] == '-'));
-  return base.size() == storePathHashLen ? ""
-                                         : string(base, storePathHashLen + 1);
+  return base.size() == storePathHashLen
+             ? ""
+             : std::string(base, storePathHashLen + 1);
 }
 
-string storePathToHash(const Path& path) {
+std::string storePathToHash(const Path& path) {
   auto base = baseNameOf(path);
   assert(base.size() >= storePathHashLen);
-  return string(base, 0, storePathHashLen);
+  return std::string(base, 0, storePathHashLen);
 }
 
-void checkStoreName(const string& name) {
-  string validChars = "+-._?=";
+void checkStoreName(const std::string& name) {
+  std::string validChars = "+-._?=";
 
   auto baseError =
       format(
@@ -90,7 +91,7 @@ void checkStoreName(const string& name) {
 
   /* Disallow names starting with a dot for possible security
      reasons (e.g., "." and ".."). */
-  if (string(name, 0, 1) == ".") {
+  if (std::string(name, 0, 1) == ".") {
     throw Error(baseError % "it is illegal to start the name with a period");
   }
   /* Disallow names longer than 211 characters. ext4’s max is 256,
@@ -100,7 +101,7 @@ void checkStoreName(const string& name) {
   }
   for (auto& i : name) {
     if (!((i >= 'A' && i <= 'Z') || (i >= 'a' && i <= 'z') ||
-          (i >= '0' && i <= '9') || validChars.find(i) != string::npos)) {
+          (i >= '0' && i <= '9') || validChars.find(i) != std::string::npos)) {
       throw Error(baseError % (format("the '%1%' character is invalid") % i));
     }
   }
@@ -176,10 +177,11 @@ void checkStoreName(const string& name) {
    "source:".
 */
 
-Path Store::makeStorePath(const string& type, const Hash& hash,
-                          const string& name) const {
+Path Store::makeStorePath(const std::string& type, const Hash& hash,
+                          const std::string& name) const {
   /* e.g., "source:sha256:1abc...:/nix/store:foo.tar.gz" */
-  string s = type + ":" + hash.to_string(Base16) + ":" + storeDir + ":" + name;
+  std::string s =
+      type + ":" + hash.to_string(Base16) + ":" + storeDir + ":" + name;
 
   checkStoreName(name);
 
@@ -188,31 +190,32 @@ Path Store::makeStorePath(const string& type, const Hash& hash,
          "-" + name;
 }
 
-Path Store::makeOutputPath(const string& id, const Hash& hash,
-                           const string& name) const {
+Path Store::makeOutputPath(const std::string& id, const Hash& hash,
+                           const std::string& name) const {
   return makeStorePath("output:" + id, hash,
                        name + (id == "out" ? "" : "-" + id));
 }
 
 Path Store::makeFixedOutputPath(bool recursive, const Hash& hash,
-                                const string& name) const {
+                                const std::string& name) const {
   return hash.type == htSHA256 && recursive
              ? makeStorePath("source", hash, name)
              : makeStorePath(
                    "output:out",
-                   hashString(htSHA256,
-                              "fixed:out:" + (recursive ? (string) "r:" : "") +
-                                  hash.to_string(Base16) + ":"),
+                   hashString(
+                       htSHA256,
+                       "fixed:out:" + (recursive ? (std::string) "r:" : "") +
+                           hash.to_string(Base16) + ":"),
                    name);
 }
 
-Path Store::makeTextPath(const string& name, const Hash& hash,
+Path Store::makeTextPath(const std::string& name, const Hash& hash,
                          const PathSet& references) const {
   assert(hash.type == htSHA256);
   /* Stuff the references (if any) into the type.  This is a bit
      hacky, but we can't put them in `s' since that would be
      ambiguous. */
-  string type = "text";
+  std::string type = "text";
   for (auto& i : references) {
     type += ":";
     type += i;
@@ -220,7 +223,7 @@ Path Store::makeTextPath(const string& name, const Hash& hash,
   return makeStorePath(type, hash, name);
 }
 
-std::pair<Path, Hash> Store::computeStorePathForPath(const string& name,
+std::pair<Path, Hash> Store::computeStorePathForPath(const std::string& name,
                                                      const Path& srcPath,
                                                      bool recursive,
                                                      HashType hashAlgo,
@@ -231,7 +234,8 @@ std::pair<Path, Hash> Store::computeStorePathForPath(const string& name,
   return std::pair<Path, Hash>(dstPath, h);
 }
 
-Path Store::computeStorePathForText(const string& name, const string& s,
+Path Store::computeStorePathForText(const std::string& name,
+                                    const std::string& s,
                                     const PathSet& references) const {
   return makeTextPath(name, hashString(htSHA256, s), references);
 }
@@ -428,9 +432,9 @@ PathSet Store::queryValidPaths(const PathSet& paths,
 /* Return a string accepted by decodeValidPathInfo() that
    registers the specified paths as valid.  Note: it's the
    responsibility of the caller to provide a closure. */
-string Store::makeValidityRegistration(const PathSet& paths, bool showDerivers,
-                                       bool showHash) {
-  string s = s;
+std::string Store::makeValidityRegistration(const PathSet& paths,
+                                            bool showDerivers, bool showHash) {
+  std::string s = s;
 
   for (auto& i : paths) {
     s += i + "\n";
@@ -710,7 +714,7 @@ ValidPathInfo decodeValidPathInfo(std::istream& str, bool hashGiven) {
     return info;
   }
   if (hashGiven) {
-    string s;
+    std::string s;
     getline(str, s);
     info.narHash = Hash(s, htSHA256);
     getline(str, s);
@@ -719,7 +723,7 @@ ValidPathInfo decodeValidPathInfo(std::istream& str, bool hashGiven) {
     }
   }
   getline(str, info.deriver);
-  string s;
+  std::string s;
   int n;
   getline(str, s);
   if (!string2Int(s, n)) {
@@ -735,8 +739,8 @@ ValidPathInfo decodeValidPathInfo(std::istream& str, bool hashGiven) {
   return info;
 }
 
-string showPaths(const PathSet& paths) {
-  string s;
+std::string showPaths(const PathSet& paths) {
+  std::string s;
   for (auto& i : paths) {
     if (!s.empty()) {
       s += ", ";
diff --git a/third_party/nix/src/libstore/store-api.hh b/third_party/nix/src/libstore/store-api.hh
index 242a3e6562..cf2520c6ca 100644
--- a/third_party/nix/src/libstore/store-api.hh
+++ b/third_party/nix/src/libstore/store-api.hh
@@ -18,12 +18,14 @@
 
 namespace nix {
 
-MakeError(SubstError, Error)
-    MakeError(BuildError, Error) /* denotes a permanent build failure */
-    MakeError(InvalidPath, Error) MakeError(Unsupported, Error)
-        MakeError(SubstituteGone, Error) MakeError(SubstituterDisabled, Error)
-
-            struct BasicDerivation;
+MakeError(SubstError, Error);
+MakeError(BuildError, Error); /* denotes a permanent build failure */
+MakeError(InvalidPath, Error);
+MakeError(Unsupported, Error);
+MakeError(SubstituteGone, Error);
+MakeError(SubstituterDisabled, Error);
+
+struct BasicDerivation;
 struct Derivation;
 class FSAccessor;
 class NarInfoDiskCache;
@@ -175,7 +177,7 @@ struct ValidPathInfo {
   virtual ~ValidPathInfo() {}
 };
 
-typedef list<ValidPathInfo> ValidPathInfos;
+typedef std::list<ValidPathInfo> ValidPathInfos;
 
 enum BuildMode { bmNormal, bmRepair, bmCheck };
 
@@ -274,23 +276,23 @@ class Store : public std::enable_shared_from_this<Store>, public Config {
   Path followLinksToStorePath(const Path& path) const;
 
   /* Constructs a unique store path name. */
-  Path makeStorePath(const string& type, const Hash& hash,
-                     const string& name) const;
+  Path makeStorePath(const std::string& type, const Hash& hash,
+                     const std::string& name) const;
 
-  Path makeOutputPath(const string& id, const Hash& hash,
-                      const string& name) const;
+  Path makeOutputPath(const std::string& id, const Hash& hash,
+                      const std::string& name) const;
 
   Path makeFixedOutputPath(bool recursive, const Hash& hash,
-                           const string& name) const;
+                           const std::string& name) const;
 
-  Path makeTextPath(const string& name, const Hash& hash,
+  Path makeTextPath(const std::string& name, const Hash& hash,
                     const PathSet& references) const;
 
   /* This is the preparatory part of addToStore(); it computes the
      store path to which srcPath is to be copied.  Returns the store
      path and the cryptographic hash of the contents of srcPath. */
   std::pair<Path, Hash> computeStorePathForPath(
-      const string& name, const Path& srcPath, bool recursive = true,
+      const std::string& name, const Path& srcPath, bool recursive = true,
       HashType hashAlgo = htSHA256,
       PathFilter& filter = defaultPathFilter) const;
 
@@ -308,7 +310,7 @@ class Store : public std::enable_shared_from_this<Store>, public Config {
      simply yield a different store path, so other users wouldn't be
      affected), but it has some backwards compatibility issues (the
      hashing scheme changes), so I'm not doing that for now. */
-  Path computeStorePathForText(const string& name, const string& s,
+  Path computeStorePathForText(const std::string& name, const std::string& s,
                                const PathSet& references) const;
 
   /* Check whether a path is valid. */
@@ -368,7 +370,7 @@ class Store : public std::enable_shared_from_this<Store>, public Config {
 
   /* Query the full store path given the hash part of a valid store
      path, or "" if the path doesn't exist. */
-  virtual Path queryPathFromHashPart(const string& hashPart) = 0;
+  virtual Path queryPathFromHashPart(const std::string& hashPart) = 0;
 
   /* Query which of the given paths have substitutes. */
   virtual PathSet querySubstitutablePaths(const PathSet& paths) { return {}; };
@@ -400,14 +402,14 @@ class Store : public std::enable_shared_from_this<Store>, public Config {
      validity the resulting path.  The resulting path is returned.
      The function object `filter' can be used to exclude files (see
      libutil/archive.hh). */
-  virtual Path addToStore(const string& name, const Path& srcPath,
+  virtual Path addToStore(const std::string& name, const Path& srcPath,
                           bool recursive = true, HashType hashAlgo = htSHA256,
                           PathFilter& filter = defaultPathFilter,
                           RepairFlag repair = NoRepair) = 0;
 
   /* Like addToStore, but the contents written to the output path is
      a regular file containing the given string. */
-  virtual Path addTextToStore(const string& name, const string& s,
+  virtual Path addTextToStore(const std::string& name, const std::string& s,
                               const PathSet& references,
                               RepairFlag repair = NoRepair) = 0;
 
@@ -484,8 +486,8 @@ class Store : public std::enable_shared_from_this<Store>, public Config {
   /* Return a string representing information about the path that
      can be loaded into the database using `nix-store --load-db' or
      `nix-store --register-validity'. */
-  string makeValidityRegistration(const PathSet& paths, bool showDerivers,
-                                  bool showHash);
+  std::string makeValidityRegistration(const PathSet& paths, bool showDerivers,
+                                       bool showHash);
 
   /* Write a JSON representation of store path metadata, such as the
      hash and the references. If ‘includeImpureInfo’ is true,
@@ -637,7 +639,7 @@ class LocalFSStore : public virtual Store {
       rootDir != "" ? rootDir + "/nix/var/log/nix" : settings.nixLogDir, "log",
       "directory where Nix will store state"};
 
-  const static string drvsLogDir;
+  const static std::string drvsLogDir;
 
   LocalFSStore(const Params& params);
 
@@ -660,15 +662,15 @@ class LocalFSStore : public virtual Store {
 };
 
 /* Extract the name part of the given store path. */
-string storePathToName(const Path& path);
+std::string storePathToName(const Path& path);
 
 /* Extract the hash part of the given store path. */
-string storePathToHash(const Path& path);
+std::string storePathToHash(const Path& path);
 
 /* Check whether ‘name’ is a valid store path name part, i.e. contains
    only the characters [a-zA-Z0-9\+\-\.\_\?\=] and doesn't start with
    a dot. */
-void checkStoreName(const string& name);
+void checkStoreName(const std::string& name);
 
 /* Copy a path from one store to another. */
 void copyStorePath(ref<Store> srcStore, const ref<Store>& dstStore,
@@ -756,7 +758,7 @@ struct RegisterStoreImplementation {
 
 /* Display a set of paths in human-readable form (i.e., between quotes
    and separated by commas). */
-string showPaths(const PathSet& paths);
+std::string showPaths(const PathSet& paths);
 
 ValidPathInfo decodeValidPathInfo(std::istream& str, bool hashGiven = false);