about summary refs log tree commit diff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/libexpr/eval.cc8
-rw-r--r--src/libexpr/eval.hh4
-rw-r--r--src/libexpr/function-trace.hh24
-rw-r--r--src/libexpr/primops.cc10
-rw-r--r--src/libstore/build.cc72
-rw-r--r--src/libstore/download.cc4
-rw-r--r--src/libstore/download.hh3
-rw-r--r--src/libstore/gc.cc70
-rw-r--r--src/libstore/globals.hh6
-rw-r--r--src/libstore/local-store.cc9
-rw-r--r--src/libstore/local-store.hh2
-rw-r--r--src/libstore/pathlocks.cc128
-rw-r--r--src/libstore/pathlocks.hh4
-rw-r--r--src/libutil/logging.hh2
-rw-r--r--src/libutil/serialise.hh30
-rw-r--r--src/libutil/util.cc23
-rw-r--r--src/libutil/util.hh2
-rw-r--r--src/nix-env/nix-env.cc15
-rw-r--r--src/nix-store/nix-store.cc12
-rw-r--r--src/nix/progress-bar.cc16
20 files changed, 285 insertions, 159 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index d8e10d9f20e1..9f4b6b411a72 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -9,6 +9,7 @@
 #include "json.hh"
 
 #include <algorithm>
+#include <chrono>
 #include <cstring>
 #include <unistd.h>
 #include <sys/time.h>
@@ -16,7 +17,6 @@
 #include <iostream>
 #include <fstream>
 
-#include <sys/time.h>
 #include <sys/resource.h>
 
 #if HAVE_BOEHMGC
@@ -1094,9 +1094,13 @@ void EvalState::callPrimOp(Value & fun, Value & arg, Value & v, const Pos & pos)
     }
 }
 
-
 void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & pos)
 {
+    std::optional<FunctionCallTrace> trace;
+    if (evalSettings.traceFunctionCalls) {
+        trace.emplace(pos);
+    }
+
     forceValue(fun, pos);
 
     if (fun.type == tPrimOp || fun.type == tPrimOpApp) {
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index a314e01e0a71..22472fd726b2 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -6,6 +6,7 @@
 #include "symbol-table.hh"
 #include "hash.hh"
 #include "config.hh"
+#include "function-trace.hh"
 
 #include <map>
 #include <unordered_map>
@@ -349,6 +350,9 @@ struct EvalSettings : Config
 
     Setting<Strings> allowedUris{this, {}, "allowed-uris",
         "Prefixes of URIs that builtin functions such as fetchurl and fetchGit are allowed to fetch."};
+
+    Setting<bool> traceFunctionCalls{this, false, "trace-function-calls",
+        "Emit log messages for each function entry and exit at the 'vomit' log level (-vvvv)"};
 };
 
 extern EvalSettings evalSettings;
diff --git a/src/libexpr/function-trace.hh b/src/libexpr/function-trace.hh
new file mode 100644
index 000000000000..8234b760312f
--- /dev/null
+++ b/src/libexpr/function-trace.hh
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "eval.hh"
+#include <sys/time.h>
+
+namespace nix {
+
+struct FunctionCallTrace
+{
+    const Pos & pos;
+
+    FunctionCallTrace(const Pos & pos) : pos(pos) {
+        auto duration = std::chrono::high_resolution_clock::now().time_since_epoch();
+        auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(duration);
+        vomit("function-trace entered %1% at %2%", pos, ns.count());
+    }
+
+    ~FunctionCallTrace() {
+        auto duration = std::chrono::high_resolution_clock::now().time_since_epoch();
+        auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(duration);
+        vomit("function-trace exited %1% at %2%", pos, ns.count());
+    }
+};
+}
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 070e72f3a966..350dba47409e 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -832,8 +832,14 @@ static void prim_pathExists(EvalState & state, const Pos & pos, Value * * args,
 {
     PathSet context;
     Path path = state.coerceToPath(pos, *args[0], context);
-    if (!context.empty())
-        throw EvalError(format("string '%1%' cannot refer to other paths, at %2%") % path % pos);
+    try {
+        state.realiseContext(context);
+    } catch (InvalidPathError & e) {
+        throw EvalError(format(
+                "cannot check the existence of '%1%', since path '%2%' is not valid, at %3%")
+            % path % e.path % pos);
+    }
+
     try {
         mkBool(v, pathExists(state.checkSourcePath(path)));
     } catch (SysError & e) {
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 96e9b8edda0a..be52b66a7def 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1629,6 +1629,61 @@ void DerivationGoal::buildDone()
            being valid. */
         registerOutputs();
 
+        if (settings.postBuildHook != "") {
+            Activity act(*logger, lvlInfo, actPostBuildHook,
+                fmt("running post-build-hook '%s'", settings.postBuildHook),
+                Logger::Fields{drvPath});
+            PushActivity pact(act.id);
+            auto outputPaths = drv->outputPaths();
+            std::map<std::string, std::string> hookEnvironment = getEnv();
+
+            hookEnvironment.emplace("DRV_PATH", drvPath);
+            hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", outputPaths)));
+
+            RunOptions opts(settings.postBuildHook, {});
+            opts.environment = hookEnvironment;
+
+            struct LogSink : Sink {
+                Activity & act;
+                std::string currentLine;
+
+                LogSink(Activity & act) : act(act) { }
+
+                void operator() (const unsigned char * data, size_t len) override {
+                    for (size_t i = 0; i < len; i++) {
+                        auto c = data[i];
+
+                        if (c == '\n') {
+                            flushLine();
+                        } else {
+                            currentLine += c;
+                        }
+                    }
+                }
+
+                void flushLine() {
+                    if (settings.verboseBuild) {
+                        printError("post-build-hook: " + currentLine);
+                    } else {
+                        act.result(resPostBuildLogLine, currentLine);
+                    }
+                    currentLine.clear();
+                }
+
+                ~LogSink() {
+                    if (currentLine != "") {
+                        currentLine += '\n';
+                        flushLine();
+                    }
+                }
+            };
+            LogSink sink(act);
+
+            opts.standardOut = &sink;
+            opts.mergeStderrToStdout = true;
+            runProgram2(opts);
+        }
+
         if (buildMode == bmCheck) {
             done(BuildResult::Built);
             return;
@@ -4005,17 +4060,6 @@ void SubstitutionGoal::tryToRun()
         return;
     }
 
-    /* If the store path is already locked (probably by a
-       DerivationGoal), then put this goal to sleep. Note: we don't
-       acquire a lock here since that breaks addToStore(), so below we
-       handle an AlreadyLocked exception from addToStore(). The check
-       here is just an optimisation to prevent having to redo a
-       download due to a locked path. */
-    if (pathIsLockedByMe(worker.store.toRealPath(storePath))) {
-        worker.waitForAWhile(shared_from_this());
-        return;
-    }
-
     maintainRunningSubstitutions = std::make_unique<MaintainCount<uint64_t>>(worker.runningSubstitutions);
     worker.updateProgress();
 
@@ -4055,12 +4099,6 @@ void SubstitutionGoal::finished()
 
     try {
         promise.get_future().get();
-    } catch (AlreadyLocked & e) {
-        /* Probably a DerivationGoal is already building this store
-           path. Sleep for a while and try again. */
-        state = &SubstitutionGoal::init;
-        worker.waitForAWhile(shared_from_this());
-        return;
     } catch (std::exception & e) {
         printError(e.what());
 
diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 91087eebcfcb..c322d267d4f2 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -236,8 +236,6 @@ struct CurlDownloader : public Downloader
             return ((DownloadItem *) userp)->readCallback(buffer, size, nitems);
         }
 
-        long lowSpeedTimeout = 300;
-
         void init()
         {
             if (!req) req = curl_easy_init();
@@ -297,7 +295,7 @@ struct CurlDownloader : public Downloader
             curl_easy_setopt(req, CURLOPT_CONNECTTIMEOUT, downloadSettings.connectTimeout.get());
 
             curl_easy_setopt(req, CURLOPT_LOW_SPEED_LIMIT, 1L);
-            curl_easy_setopt(req, CURLOPT_LOW_SPEED_TIME, lowSpeedTimeout);
+            curl_easy_setopt(req, CURLOPT_LOW_SPEED_TIME, downloadSettings.stalledDownloadTimeout.get());
 
             /* If no file exist in the specified path, curl continues to work
                anyway as if netrc support was disabled. */
diff --git a/src/libstore/download.hh b/src/libstore/download.hh
index 3b7fff3ba4cb..c68381846948 100644
--- a/src/libstore/download.hh
+++ b/src/libstore/download.hh
@@ -24,6 +24,9 @@ struct DownloadSettings : Config
     Setting<unsigned long> connectTimeout{this, 0, "connect-timeout",
         "Timeout for connecting to servers during downloads. 0 means use curl's builtin default."};
 
+    Setting<unsigned long> stalledDownloadTimeout{this, 300, "stalled-download-timeout",
+        "Timeout (in seconds) for receiving data from servers during download. Nix cancels idle downloads after this timeout's duration."};
+
     Setting<unsigned int> tries{this, 5, "download-attempts",
         "How often Nix will attempt to download a file before giving up."};
 };
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 26e2b0dca7ca..366dbfb0a653 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -29,7 +29,7 @@ static string gcRootsDir = "gcroots";
    read.  To be precise: when they try to create a new temporary root
    file, they will block until the garbage collector has finished /
    yielded the GC lock. */
-int LocalStore::openGCLock(LockType lockType)
+AutoCloseFD LocalStore::openGCLock(LockType lockType)
 {
     Path fnGCLock = (format("%1%/%2%")
         % stateDir % gcLockName).str();
@@ -49,7 +49,7 @@ int LocalStore::openGCLock(LockType lockType)
        process that can open the file for reading can DoS the
        collector. */
 
-    return fdGCLock.release();
+    return fdGCLock;
 }
 
 
@@ -221,26 +221,22 @@ void LocalStore::findTempRoots(FDs & fds, Roots & tempRoots, bool censor)
         //FDPtr fd(new AutoCloseFD(openLockFile(path, false)));
         //if (*fd == -1) continue;
 
-        if (path != fnTempRoots) {
-
-            /* Try to acquire a write lock without blocking.  This can
-               only succeed if the owning process has died.  In that case
-               we don't care about its temporary roots. */
-            if (lockFile(fd->get(), ltWrite, false)) {
-                printError(format("removing stale temporary roots file '%1%'") % path);
-                unlink(path.c_str());
-                writeFull(fd->get(), "d");
-                continue;
-            }
-
-            /* Acquire a read lock.  This will prevent the owning process
-               from upgrading to a write lock, therefore it will block in
-               addTempRoot(). */
-            debug(format("waiting for read lock on '%1%'") % path);
-            lockFile(fd->get(), ltRead, true);
-
+        /* Try to acquire a write lock without blocking.  This can
+           only succeed if the owning process has died.  In that case
+           we don't care about its temporary roots. */
+        if (lockFile(fd->get(), ltWrite, false)) {
+            printError(format("removing stale temporary roots file '%1%'") % path);
+            unlink(path.c_str());
+            writeFull(fd->get(), "d");
+            continue;
         }
 
+        /* Acquire a read lock.  This will prevent the owning process
+           from upgrading to a write lock, therefore it will block in
+           addTempRoot(). */
+        debug(format("waiting for read lock on '%1%'") % path);
+        lockFile(fd->get(), ltRead, true);
+
         /* Read the entire file. */
         string contents = readFile(fd->get());
 
@@ -444,17 +440,22 @@ void LocalStore::findRuntimeRoots(Roots & roots, bool censor)
     }
 
 #if !defined(__linux__)
-    try {
-        std::regex lsofRegex(R"(^n(/.*)$)");
-        auto lsofLines =
-            tokenizeString<std::vector<string>>(runProgram(LSOF, true, { "-n", "-w", "-F", "n" }), "\n");
-        for (const auto & line : lsofLines) {
-            std::smatch match;
-            if (std::regex_match(line, match, lsofRegex))
-                unchecked[match[1]].emplace("{lsof}");
+    // lsof is really slow on OS X. This actually causes the gc-concurrent.sh test to fail.
+    // See: https://github.com/NixOS/nix/issues/3011
+    // Because of this we disable lsof when running the tests.
+    if (getEnv("_NIX_TEST_NO_LSOF") == "") {
+        try {
+            std::regex lsofRegex(R"(^n(/.*)$)");
+            auto lsofLines =
+                tokenizeString<std::vector<string>>(runProgram(LSOF, true, { "-n", "-w", "-F", "n" }), "\n");
+            for (const auto & line : lsofLines) {
+                std::smatch match;
+                if (std::regex_match(line, match, lsofRegex))
+                    unchecked[match[1]].emplace("{lsof}");
+            }
+        } catch (ExecError & e) {
+            /* lsof not installed, lsof failed */
         }
-    } catch (ExecError & e) {
-        /* lsof not installed, lsof failed */
     }
 #endif
 
@@ -866,7 +867,12 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
 
 void LocalStore::autoGC(bool sync)
 {
-    auto getAvail = [this]() {
+    static auto fakeFreeSpaceFile = getEnv("_NIX_TEST_FREE_SPACE_FILE", "");
+
+    auto getAvail = [this]() -> uint64_t {
+        if (!fakeFreeSpaceFile.empty())
+            return std::stoll(readFile(fakeFreeSpaceFile));
+
         struct statvfs st;
         if (statvfs(realStoreDir.c_str(), &st))
             throw SysError("getting filesystem info about '%s'", realStoreDir);
@@ -887,7 +893,7 @@ void LocalStore::autoGC(bool sync)
 
         auto now = std::chrono::steady_clock::now();
 
-        if (now < state->lastGCCheck + std::chrono::seconds(5)) return;
+        if (now < state->lastGCCheck + std::chrono::seconds(settings.minFreeCheckInterval)) return;
 
         auto avail = getAvail();
 
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index cc9534b2794d..ab1c09aa25da 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -318,6 +318,9 @@ public:
         "pre-build-hook",
         "A program to run just before a build to set derivation-specific build settings."};
 
+    Setting<std::string> postBuildHook{this, "", "post-build-hook",
+        "A program to run just after each succesful build."};
+
     Setting<std::string> netrcFile{this, fmt("%s/%s", nixConfDir, "netrc"), "netrc-file",
         "Path to the netrc file used to obtain usernames/passwords for downloads."};
 
@@ -345,6 +348,9 @@ public:
     Setting<uint64_t> maxFree{this, std::numeric_limits<uint64_t>::max(), "max-free",
         "Stop deleting garbage when free disk space is above the specified amount."};
 
+    Setting<uint64_t> minFreeCheckInterval{this, 5, "min-free-check-interval",
+        "Number of seconds between checking free disk space."};
+
     Setting<Paths> pluginFiles{this, {}, "plugin-files",
         "Plugins to dynamically load at nix initialization time."};
 };
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 485fdd691932..63b11467eb95 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1210,7 +1210,8 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
 
     bool errors = false;
 
-    /* Acquire the global GC lock to prevent a garbage collection. */
+    /* Acquire the global GC lock to get a consistent snapshot of
+       existing and valid paths. */
     AutoCloseFD fdGCLock = openGCLock(ltWrite);
 
     PathSet store;
@@ -1221,13 +1222,11 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
 
     PathSet validPaths2 = queryAllValidPaths(), validPaths, done;
 
+    fdGCLock = -1;
+
     for (auto & i : validPaths2)
         verifyPath(i, store, done, validPaths, repair, errors);
 
-    /* Release the GC lock so that checking content hashes (which can
-       take ages) doesn't block the GC or builds. */
-    fdGCLock = -1;
-
     /* Optionally, check the content hashes (slow). */
     if (checkContents) {
         printInfo("checking hashes...");
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 6b655647b031..af8b84bf5d73 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -263,7 +263,7 @@ private:
     bool isActiveTempFile(const GCState & state,
         const Path & path, const string & suffix);
 
-    int openGCLock(LockType lockType);
+    AutoCloseFD openGCLock(LockType lockType);
 
     void findRoots(const Path & path, unsigned char type, Roots & roots);
 
diff --git a/src/libstore/pathlocks.cc b/src/libstore/pathlocks.cc
index 08d1efdbeb01..2635e3940af8 100644
--- a/src/libstore/pathlocks.cc
+++ b/src/libstore/pathlocks.cc
@@ -5,9 +5,10 @@
 #include <cerrno>
 #include <cstdlib>
 
+#include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <fcntl.h>
+#include <sys/file.h>
 
 
 namespace nix {
@@ -40,17 +41,14 @@ void deleteLockFile(const Path & path, int fd)
 
 bool lockFile(int fd, LockType lockType, bool wait)
 {
-    struct flock lock;
-    if (lockType == ltRead) lock.l_type = F_RDLCK;
-    else if (lockType == ltWrite) lock.l_type = F_WRLCK;
-    else if (lockType == ltNone) lock.l_type = F_UNLCK;
+    int type;
+    if (lockType == ltRead) type = LOCK_SH;
+    else if (lockType == ltWrite) type = LOCK_EX;
+    else if (lockType == ltNone) type = LOCK_UN;
     else abort();
-    lock.l_whence = SEEK_SET;
-    lock.l_start = 0;
-    lock.l_len = 0; /* entire file */
 
     if (wait) {
-        while (fcntl(fd, F_SETLKW, &lock) != 0) {
+        while (flock(fd, type) != 0) {
             checkInterrupt();
             if (errno != EINTR)
                 throw SysError(format("acquiring/releasing lock"));
@@ -58,9 +56,9 @@ bool lockFile(int fd, LockType lockType, bool wait)
                 return false;
         }
     } else {
-        while (fcntl(fd, F_SETLK, &lock) != 0) {
+        while (flock(fd, type | LOCK_NB) != 0) {
             checkInterrupt();
-            if (errno == EACCES || errno == EAGAIN) return false;
+            if (errno == EWOULDBLOCK) return false;
             if (errno != EINTR)
                 throw SysError(format("acquiring/releasing lock"));
         }
@@ -70,14 +68,6 @@ bool lockFile(int fd, LockType lockType, bool wait)
 }
 
 
-/* This enables us to check whether are not already holding a lock on
-   a file ourselves.  POSIX locks (fcntl) suck in this respect: if we
-   close a descriptor, the previous lock will be closed as well.  And
-   there is no way to query whether we already have a lock (F_GETLK
-   only works on locks held by other processes). */
-static Sync<StringSet> lockedPaths_;
-
-
 PathLocks::PathLocks()
     : deletePaths(false)
 {
@@ -91,7 +81,7 @@ PathLocks::PathLocks(const PathSet & paths, const string & waitMsg)
 }
 
 
-bool PathLocks::lockPaths(const PathSet & _paths,
+bool PathLocks::lockPaths(const PathSet & paths,
     const string & waitMsg, bool wait)
 {
     assert(fds.empty());
@@ -99,75 +89,54 @@ bool PathLocks::lockPaths(const PathSet & _paths,
     /* Note that `fds' is built incrementally so that the destructor
        will only release those locks that we have already acquired. */
 
-    /* Sort the paths.  This assures that locks are always acquired in
-       the same order, thus preventing deadlocks. */
-    Paths paths(_paths.begin(), _paths.end());
-    paths.sort();
-
-    /* Acquire the lock for each path. */
+    /* Acquire the lock for each path in sorted order. This ensures
+       that locks are always acquired in the same order, thus
+       preventing deadlocks. */
     for (auto & path : paths) {
         checkInterrupt();
         Path lockPath = path + ".lock";
 
         debug(format("locking path '%1%'") % path);
 
-        {
-            auto lockedPaths(lockedPaths_.lock());
-            if (lockedPaths->count(lockPath)) {
-                if (!wait) return false;
-                throw AlreadyLocked("deadlock: trying to re-acquire self-held lock '%s'", lockPath);
-            }
-            lockedPaths->insert(lockPath);
-        }
-
-        try {
-
-            AutoCloseFD fd;
+        AutoCloseFD fd;
 
-            while (1) {
+        while (1) {
 
-                /* Open/create the lock file. */
-                fd = openLockFile(lockPath, true);
+            /* Open/create the lock file. */
+            fd = openLockFile(lockPath, true);
 
-                /* Acquire an exclusive lock. */
-                if (!lockFile(fd.get(), ltWrite, false)) {
-                    if (wait) {
-                        if (waitMsg != "") printError(waitMsg);
-                        lockFile(fd.get(), ltWrite, true);
-                    } else {
-                        /* Failed to lock this path; release all other
-                           locks. */
-                        unlock();
-                        lockedPaths_.lock()->erase(lockPath);
-                        return false;
-                    }
+            /* Acquire an exclusive lock. */
+            if (!lockFile(fd.get(), ltWrite, false)) {
+                if (wait) {
+                    if (waitMsg != "") printError(waitMsg);
+                    lockFile(fd.get(), ltWrite, true);
+                } else {
+                    /* Failed to lock this path; release all other
+                       locks. */
+                    unlock();
+                    return false;
                 }
-
-                debug(format("lock acquired on '%1%'") % lockPath);
-
-                /* Check that the lock file hasn't become stale (i.e.,
-                   hasn't been unlinked). */
-                struct stat st;
-                if (fstat(fd.get(), &st) == -1)
-                    throw SysError(format("statting lock file '%1%'") % lockPath);
-                if (st.st_size != 0)
-                    /* This lock file has been unlinked, so we're holding
-                       a lock on a deleted file.  This means that other
-                       processes may create and acquire a lock on
-                       `lockPath', and proceed.  So we must retry. */
-                    debug(format("open lock file '%1%' has become stale") % lockPath);
-                else
-                    break;
             }
 
-            /* Use borrow so that the descriptor isn't closed. */
-            fds.push_back(FDPair(fd.release(), lockPath));
-
-        } catch (...) {
-            lockedPaths_.lock()->erase(lockPath);
-            throw;
+            debug(format("lock acquired on '%1%'") % lockPath);
+
+            /* Check that the lock file hasn't become stale (i.e.,
+               hasn't been unlinked). */
+            struct stat st;
+            if (fstat(fd.get(), &st) == -1)
+                throw SysError(format("statting lock file '%1%'") % lockPath);
+            if (st.st_size != 0)
+                /* This lock file has been unlinked, so we're holding
+                   a lock on a deleted file.  This means that other
+                   processes may create and acquire a lock on
+                   `lockPath', and proceed.  So we must retry. */
+                debug(format("open lock file '%1%' has become stale") % lockPath);
+            else
+                break;
         }
 
+        /* Use borrow so that the descriptor isn't closed. */
+        fds.push_back(FDPair(fd.release(), lockPath));
     }
 
     return true;
@@ -189,8 +158,6 @@ void PathLocks::unlock()
     for (auto & i : fds) {
         if (deletePaths) deleteLockFile(i.second, i.first);
 
-        lockedPaths_.lock()->erase(i.second);
-
         if (close(i.first) == -1)
             printError(
                 format("error (ignored): cannot close lock file on '%1%'") % i.second);
@@ -208,11 +175,4 @@ void PathLocks::setDeletion(bool deletePaths)
 }
 
 
-bool pathIsLockedByMe(const Path & path)
-{
-    Path lockPath = path + ".lock";
-    return lockedPaths_.lock()->count(lockPath);
-}
-
-
 }
diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh
index db51f950a320..411da022295d 100644
--- a/src/libstore/pathlocks.hh
+++ b/src/libstore/pathlocks.hh
@@ -16,8 +16,6 @@ enum LockType { ltRead, ltWrite, ltNone };
 
 bool lockFile(int fd, LockType lockType, bool wait);
 
-MakeError(AlreadyLocked, Error);
-
 class PathLocks
 {
 private:
@@ -37,6 +35,4 @@ public:
     void setDeletion(bool deletePaths);
 };
 
-bool pathIsLockedByMe(const Path & path);
-
 }
diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh
index 5f221944594b..5df03da74e00 100644
--- a/src/libutil/logging.hh
+++ b/src/libutil/logging.hh
@@ -26,6 +26,7 @@ typedef enum {
     actVerifyPaths = 107,
     actSubstitute = 108,
     actQueryPathInfo = 109,
+    actPostBuildHook = 110,
 } ActivityType;
 
 typedef enum {
@@ -36,6 +37,7 @@ typedef enum {
     resSetPhase = 104,
     resProgress = 105,
     resSetExpected = 106,
+    resPostBuildLogLine = 107,
 } ResultType;
 
 typedef uint64_t ActivityId;
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 969e4dff383d..a344a5ac7520 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -179,6 +179,36 @@ struct TeeSource : Source
     }
 };
 
+/* A reader that consumes the original Source until 'size'. */
+struct SizedSource : Source
+{
+    Source & orig;
+    size_t remain;
+    SizedSource(Source & orig, size_t size)
+        : orig(orig), remain(size) { }
+    size_t read(unsigned char * data, size_t len)
+    {
+        if (this->remain <= 0) {
+            throw EndOfFile("sized: unexpected end-of-file");
+        }
+        len = std::min(len, this->remain);
+        size_t n = this->orig.read(data, len);
+        this->remain -= n;
+        return n;
+    }
+
+    /* Consume the original source until no remain data is left to consume. */
+    size_t drainAll()
+    {
+        std::vector<unsigned char> buf(8192);
+        size_t sum = 0;
+        while (this->remain > 0) {
+            size_t n = read(buf.data(), buf.size());
+            sum += n;
+        }
+        return sum;
+    }
+};
 
 /* Convert a function into a sink. */
 struct LambdaSink : Sink
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 17aee2d5c3d0..44fa72482552 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -84,6 +84,15 @@ void clearEnv()
         unsetenv(name.first.c_str());
 }
 
+void replaceEnv(std::map<std::string, std::string> newEnv)
+{
+    clearEnv();
+    for (auto newEnvVar : newEnv)
+    {
+        setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1);
+    }
+}
+
 
 Path absPath(Path path, Path dir)
 {
@@ -1019,10 +1028,22 @@ void runProgram2(const RunOptions & options)
     if (options.standardOut) out.create();
     if (source) in.create();
 
+    ProcessOptions processOptions;
+    // vfork implies that the environment of the main process and the fork will
+    // be shared (technically this is undefined, but in practice that's the
+    // case), so we can't use it if we alter the environment
+    if (options.environment)
+        processOptions.allowVfork = false;
+
     /* Fork. */
     Pid pid = startProcess([&]() {
+        if (options.environment)
+            replaceEnv(*options.environment);
         if (options.standardOut && dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
             throw SysError("dupping stdout");
+        if (options.mergeStderrToStdout)
+            if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
+                throw SysError("cannot dup stdout into stderr");
         if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1)
             throw SysError("dupping stdin");
 
@@ -1047,7 +1068,7 @@ void runProgram2(const RunOptions & options)
             execv(options.program.c_str(), stringsToCharPtrs(args_).data());
 
         throw SysError("executing '%1%'", options.program);
-    });
+    }, processOptions);
 
     out.writeSide = -1;
 
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index fce3cab8def5..b538a0b41ce8 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -270,12 +270,14 @@ struct RunOptions
     std::optional<uid_t> uid;
     std::optional<uid_t> gid;
     std::optional<Path> chdir;
+    std::optional<std::map<std::string, std::string>> environment;
     Path program;
     bool searchPath = true;
     Strings args;
     std::optional<std::string> input;
     Source * standardIn = nullptr;
     Sink * standardOut = nullptr;
+    bool mergeStderrToStdout = false;
     bool _killStderr = false;
 
     RunOptions(const Path & program, const Strings & args)
diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index 56ed75daee44..87b2e43f063d 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -860,7 +860,10 @@ static void queryJSON(Globals & globals, vector<DrvInfo> & elems)
     for (auto & i : elems) {
         JSONObject pkgObj = topObj.object(i.attrPath);
 
-        pkgObj.attr("name", i.queryName());
+        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");
@@ -1026,10 +1029,14 @@ static void opQuery(Globals & globals, Strings opFlags, Strings opArgs)
             else if (printAttrPath)
                 columns.push_back(i.attrPath);
 
-            if (xmlOutput)
-                attrs["name"] = i.queryName();
-            else if (printName)
+            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
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index f324056bb3a1..0cbceb02f31e 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -950,8 +950,16 @@ static void opServe(Strings opFlags, Strings opArgs)
                 info.sigs = readStrings<StringSet>(in);
                 in >> info.ca;
 
-                // FIXME: race if addToStore doesn't read source?
-                store->addToStore(info, in, NoRepair, NoCheckSigs);
+                if (info.narSize == 0) {
+                    throw Error("narInfo is too old and missing the narSize field");
+                }
+
+                SizedSource sizedSource(in, info.narSize);
+
+                store->addToStore(info, sizedSource, NoRepair, NoCheckSigs);
+
+                // consume all the data that has been sent before continuing.
+                sizedSource.drainAll();
 
                 out << 1; // indicate success
 
diff --git a/src/nix/progress-bar.cc b/src/nix/progress-bar.cc
index b1c1d87de1a2..c0bcfb0c91bc 100644
--- a/src/nix/progress-bar.cc
+++ b/src/nix/progress-bar.cc
@@ -170,6 +170,14 @@ public:
                 name, sub);
         }
 
+        if (type == actPostBuildHook) {
+            auto name = storePathToName(getS(fields, 0));
+            if (hasSuffix(name, ".drv"))
+                name.resize(name.size() - 4);
+            i->s = fmt("post-build " ANSI_BOLD "%s" ANSI_NORMAL, name);
+            i->name = DrvName(name).name;
+        }
+
         if (type == actQueryPathInfo) {
             auto name = storePathToName(getS(fields, 0));
             i->s = fmt("querying " ANSI_BOLD "%s" ANSI_NORMAL " on %s", name, getS(fields, 1));
@@ -228,14 +236,18 @@ public:
             update(*state);
         }
 
-        else if (type == resBuildLogLine) {
+        else if (type == resBuildLogLine || type == resPostBuildLogLine) {
             auto lastLine = trim(getS(fields, 0));
             if (!lastLine.empty()) {
                 auto i = state->its.find(act);
                 assert(i != state->its.end());
                 ActInfo info = *i->second;
                 if (printBuildLogs) {
-                    log(*state, lvlInfo, ANSI_FAINT + info.name.value_or("unnamed") + "> " + ANSI_NORMAL + lastLine);
+                    auto suffix = "> ";
+                    if (type == resPostBuildLogLine) {
+                        suffix = " (post)> ";
+                    }
+                    log(*state, lvlInfo, ANSI_FAINT + info.name.value_or("unnamed") + suffix + ANSI_NORMAL + lastLine);
                 } else {
                     state->activities.erase(i->second);
                     info.lastLine = lastLine;