6 files changed, 116 insertions, 787 deletions

diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index 47c7f9728e..f9fd61adde 100644
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -84,6 +84,7 @@ struct HookInstance;
 
 /* A pointer to a goal. */
 class Goal;
+class DerivationGoal;
 typedef std::shared_ptr<Goal> GoalPtr;
 typedef std::weak_ptr<Goal> WeakGoalPtr;
 
@@ -174,10 +175,10 @@ public:
         return exitCode;
     }
 
-    /* Cancel the goal.  It should wake up its waiters, get rid of any
-       running child processes that are being monitored by the worker
-       (important!), etc. */
-    virtual void cancel(bool timeout) = 0;
+    /* Callback in case of a timeout.  It should wake up its waiters,
+       get rid of any running child processes that are being monitored
+       by the worker (important!), etc. */
+    virtual void timedOut() = 0;
 
     virtual string key() = 0;
 
@@ -799,11 +800,13 @@ private:
        result. */
     ValidPathInfos prevInfos;
 
+    BuildResult result;
+
 public:
     DerivationGoal(const Path & drvPath, const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode = bmNormal);
     ~DerivationGoal();
 
-    void cancel(bool timeout);
+    void timedOut() override;
 
     string key()
     {
@@ -824,6 +827,8 @@ public:
     /* Add wanted outputs to an already existing derivation goal. */
     void addWantedOutputs(const StringSet & outputs);
 
+    BuildResult getResult() { return result; }
+
 private:
     /* The states. */
     void init();
@@ -874,6 +879,8 @@ private:
     Path addHashRewrite(const Path & path);
 
     void repairClosure();
+
+    void done(BuildResult::Status status, const string & msg = "");
 };
 
 
@@ -933,12 +940,12 @@ void DerivationGoal::killChild()
 }
 
 
-void DerivationGoal::cancel(bool timeout)
+void DerivationGoal::timedOut()
 {
-    if (settings.printBuildTrace && timeout)
+    if (settings.printBuildTrace)
         printMsg(lvlError, format("@ build-failed %1% - timeout") % drvPath);
     killChild();
-    amDone(ecFailed);
+    done(BuildResult::TimedOut);
 }
 
 
@@ -991,8 +998,8 @@ void DerivationGoal::haveDerivation()
     trace("loading derivation");
 
     if (nrFailed != 0) {
-        printMsg(lvlError, format("cannot build missing derivation `%1%'") % drvPath);
-        amDone(ecFailed);
+        printMsg(lvlError, format("cannot build missing derivation ‘%1%’") % drvPath);
+        done(BuildResult::MiscFailure);
         return;
     }
 
@@ -1014,7 +1021,7 @@ void DerivationGoal::haveDerivation()
 
     /* If they are all valid, then we're done. */
     if (invalidOutputs.size() == 0 && buildMode == bmNormal) {
-        amDone(ecSuccess);
+        done(BuildResult::AlreadyValid);
         return;
     }
 
@@ -1059,7 +1066,7 @@ void DerivationGoal::outputsSubstituted()
 
     unsigned int nrInvalid = checkPathValidity(false, buildMode == bmRepair).size();
     if (buildMode == bmNormal && nrInvalid == 0) {
-        amDone(ecSuccess);
+        done(BuildResult::Substituted);
         return;
     }
     if (buildMode == bmRepair && nrInvalid == 0) {
@@ -1132,7 +1139,7 @@ void DerivationGoal::repairClosure()
     }
 
     if (waitees.empty()) {
-        amDone(ecSuccess);
+        done(BuildResult::AlreadyValid);
         return;
     }
 
@@ -1144,8 +1151,8 @@ void DerivationGoal::closureRepaired()
 {
     trace("closure repaired");
     if (nrFailed > 0)
-        throw Error(format("some paths in the output closure of derivation `%1%' could not be repaired") % drvPath);
-    amDone(ecSuccess);
+        throw Error(format("some paths in the output closure of derivation ‘%1%’ could not be repaired") % drvPath);
+    done(BuildResult::AlreadyValid);
 }
 
 
@@ -1157,7 +1164,7 @@ void DerivationGoal::inputsRealised()
         printMsg(lvlError,
             format("cannot build derivation `%1%': %2% dependencies couldn't be built")
             % drvPath % nrFailed);
-        amDone(ecFailed);
+        done(BuildResult::DependencyFailed);
         return;
     }
 
@@ -1286,7 +1293,7 @@ void DerivationGoal::tryToBuild()
     if (buildMode != bmCheck && validPaths.size() == drv.outputs.size()) {
         debug(format("skipping build of derivation `%1%', someone beat us to it") % drvPath);
         outputLocks.setDeletion(true);
-        amDone(ecSuccess);
+        done(BuildResult::AlreadyValid);
         return;
     }
 
@@ -1358,7 +1365,7 @@ void DerivationGoal::tryToBuild()
             printMsg(lvlError, format("@ build-failed %1% - %2% %3%")
                 % drvPath % 0 % e.msg());
         worker.permanentFailure = true;
-        amDone(ecFailed);
+        done(BuildResult::InputRejected, e.msg());
         return;
     }
 
@@ -1473,7 +1480,7 @@ void DerivationGoal::buildDone()
         registerOutputs();
 
         if (buildMode == bmCheck) {
-            amDone(ecSuccess);
+            done(BuildResult::Built);
             return;
         }
 
@@ -1508,10 +1515,12 @@ void DerivationGoal::buildDone()
         outputLocks.unlock();
         buildUser.release();
 
+        BuildResult::Status st = BuildResult::MiscFailure;
+
         if (hook && WIFEXITED(status) && WEXITSTATUS(status) == 101) {
             if (settings.printBuildTrace)
                 printMsg(lvlError, format("@ build-failed %1% - timeout") % drvPath);
-            worker.timedOut = true;
+            st = BuildResult::TimedOut;
         }
 
         else if (hook && (!WIFEXITED(status) || WEXITSTATUS(status) != 100)) {
@@ -1524,7 +1533,11 @@ void DerivationGoal::buildDone()
             if (settings.printBuildTrace)
                 printMsg(lvlError, format("@ build-failed %1% - %2% %3%")
                     % drvPath % 1 % e.msg());
-            worker.permanentFailure = !fixedOutput && !diskFull;
+
+            st =
+                statusOk(status) ? BuildResult::OutputRejected :
+                fixedOutput || diskFull ? BuildResult::TransientFailure :
+                BuildResult::PermanentFailure;
 
             /* Register the outputs of this build as "failed" so we
                won't try to build them again (negative caching).
@@ -1538,7 +1551,7 @@ void DerivationGoal::buildDone()
                     worker.store.registerFailedPath(i->second.path);
         }
 
-        amDone(ecFailed);
+        done(st, e.msg());
         return;
     }
 
@@ -1548,7 +1561,7 @@ void DerivationGoal::buildDone()
     if (settings.printBuildTrace)
         printMsg(lvlError, format("@ build-succeeded %1% -") % drvPath);
 
-    amDone(ecSuccess);
+    done(BuildResult::Built);
 }
 
 
@@ -1700,11 +1713,11 @@ void DerivationGoal::startBuilder()
     /* Create a temporary directory where the build will take
        place. */
     auto drvName = storePathToName(drvPath);
-    tmpDir = createTempDir("", "nix-build-" + drvName, false, false, 0700);
+    tmpDir = createTempDir("", "guix-build-" + drvName, false, false, 0700);
 
     /* In a sandbox, for determinism, always use the same temporary
        directory. */
-    tmpDirInSandbox = useChroot ? "/tmp/nix-build-" + drvName + "-0" : tmpDir;
+    tmpDirInSandbox = useChroot ? "/tmp/guix-build-" + drvName + "-0" : tmpDir;
 
     /* For convenience, set an environment pointing to the top build
        directory. */
@@ -2579,7 +2592,7 @@ void DerivationGoal::handleChildOutput(int fd, const string & data)
             printMsg(lvlError,
                 format("%1% killed after writing more than %2% bytes of log output")
                 % getName() % settings.maxLogSize);
-            cancel(true); // not really a timeout, but close enough
+            timedOut(); // not really a timeout, but close enough
             return;
         }
         if (verbosity >= settings.buildVerbosity)
@@ -2628,8 +2641,7 @@ bool DerivationGoal::pathFailed(const Path & path)
     if (settings.printBuildTrace)
         printMsg(lvlError, format("@ build-failed %1% - cached") % drvPath);
 
-    worker.permanentFailure = true;
-    amDone(ecFailed);
+    done(BuildResult::CachedFailure);
 
     return true;
 }
@@ -2649,6 +2661,18 @@ Path DerivationGoal::addHashRewrite(const Path & path)
 }
 
 
+void DerivationGoal::done(BuildResult::Status status, const string & msg)
+{
+    result.status = status;
+    result.errorMsg = msg;
+    amDone(result.success() ? ecSuccess : ecFailed);
+    if (result.status == BuildResult::TimedOut)
+        worker.timedOut = true;
+    if (result.status == BuildResult::PermanentFailure || result.status == BuildResult::CachedFailure)
+        worker.permanentFailure = true;
+}
+
+
 //////////////////////////////////////////////////////////////////////
 
 
@@ -2698,7 +2722,7 @@ public:
     SubstitutionGoal(const Path & storePath, Worker & worker, bool repair = false);
     ~SubstitutionGoal();
 
-    void cancel(bool timeout);
+    void timedOut();
 
     string key()
     {
@@ -2743,9 +2767,9 @@ SubstitutionGoal::~SubstitutionGoal()
 }
 
 
-void SubstitutionGoal::cancel(bool timeout)
+void SubstitutionGoal::timedOut()
 {
-    if (settings.printBuildTrace && timeout)
+    if (settings.printBuildTrace)
         printMsg(lvlError, format("@ substituter-failed %1% timeout") % storePath);
     if (pid != -1) {
         pid_t savedPid = pid;
@@ -3066,7 +3090,8 @@ Worker::~Worker()
 }
 
 
-GoalPtr Worker::makeDerivationGoal(const Path & path, const StringSet & wantedOutputs, BuildMode buildMode)
+GoalPtr Worker::makeDerivationGoal(const Path & path,
+    const StringSet & wantedOutputs, BuildMode buildMode)
 {
     GoalPtr goal = derivationGoals[path].lock();
     if (!goal) {
@@ -3323,7 +3348,7 @@ void Worker::waitForInput()
     /* Since goals may be canceled from inside the loop below (causing
        them go be erased from the `children' map), we have to be
        careful that we don't keep iterators alive across calls to
-       cancel(). */
+       timedOut(). */
     set<pid_t> pids;
     foreach (Children::iterator, i, children) pids.insert(i->first);
 
@@ -3365,8 +3390,7 @@ void Worker::waitForInput()
             printMsg(lvlError,
                 format("%1% timed out after %2% seconds of silence")
                 % goal->getName() % settings.maxSilentTime);
-            goal->cancel(true);
-            timedOut = true;
+            goal->timedOut();
         }
 
         else if (goal->getExitCode() == Goal::ecBusy &&
@@ -3377,8 +3401,7 @@ void Worker::waitForInput()
             printMsg(lvlError,
                 format("%1% timed out after %2% seconds")
                 % goal->getName() % settings.buildTimeout);
-            goal->cancel(true);
-            timedOut = true;
+            goal->timedOut();
         }
     }
 
diff --git a/nix/libstore/remote-store.cc b/nix/libstore/remote-store.cc
deleted file mode 100644
index 324ef5eb30..0000000000
--- a/nix/libstore/remote-store.cc
+++ /dev/null
@@ -1,639 +0,0 @@
-#include "serialise.hh"
-#include "util.hh"
-#include "remote-store.hh"
-#include "worker-protocol.hh"
-#include "archive.hh"
-#include "affinity.hh"
-#include "globals.hh"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-#include <errno.h>
-#include <fcntl.h>
-
-#include <iostream>
-#include <unistd.h>
-#include <cstring>
-
-namespace nix {
-
-
-Path readStorePath(Source & from)
-{
-    Path path = readString(from);
-    assertStorePath(path);
-    return path;
-}
-
-
-template<class T> T readStorePaths(Source & from)
-{
-    T paths = readStrings<T>(from);
-    foreach (typename T::iterator, i, paths) assertStorePath(*i);
-    return paths;
-}
-
-template PathSet readStorePaths(Source & from);
-
-
-RemoteStore::RemoteStore()
-{
-    initialised = false;
-}
-
-
-void RemoteStore::openConnection(bool reserveSpace)
-{
-    if (initialised) return;
-    initialised = true;
-
-    string remoteMode = getEnv("NIX_REMOTE");
-
-    if (remoteMode == "daemon")
-        /* Connect to a daemon that does the privileged work for
-           us. */
-        connectToDaemon();
-    else
-        throw Error(format("invalid setting for NIX_REMOTE, `%1%'") % remoteMode);
-
-    from.fd = fdSocket;
-    to.fd = fdSocket;
-
-    /* Send the magic greeting, check for the reply. */
-    try {
-        writeInt(WORKER_MAGIC_1, to);
-        to.flush();
-        unsigned int magic = readInt(from);
-        if (magic != WORKER_MAGIC_2) throw Error("protocol mismatch");
-
-        daemonVersion = readInt(from);
-        if (GET_PROTOCOL_MAJOR(daemonVersion) != GET_PROTOCOL_MAJOR(PROTOCOL_VERSION))
-            throw Error("Nix daemon protocol version not supported");
-        writeInt(PROTOCOL_VERSION, to);
-
-        if (GET_PROTOCOL_MINOR(daemonVersion) >= 14) {
-            int cpu = settings.lockCPU ? lockToCurrentCPU() : -1;
-            if (cpu != -1) {
-                writeInt(1, to);
-                writeInt(cpu, to);
-            } else
-                writeInt(0, to);
-        }
-
-        if (GET_PROTOCOL_MINOR(daemonVersion) >= 11)
-            writeInt(reserveSpace, to);
-
-        processStderr();
-    }
-    catch (Error & e) {
-        throw Error(format("cannot start daemon worker: %1%") % e.msg());
-    }
-
-    setOptions();
-}
-
-
-void RemoteStore::connectToDaemon()
-{
-    fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
-    if (fdSocket == -1)
-        throw SysError("cannot create Unix domain socket");
-    closeOnExec(fdSocket);
-
-    string socketPath = settings.nixDaemonSocketFile;
-
-    /* Urgh, sockaddr_un allows path names of only 108 characters.  So
-       chdir to the socket directory so that we can pass a relative
-       path name.  !!! this is probably a bad idea in multi-threaded
-       applications... */
-    AutoCloseFD fdPrevDir = open(".", O_RDONLY);
-    if (fdPrevDir == -1) throw SysError("couldn't open current directory");
-    if (chdir(dirOf(socketPath).c_str()) == -1) throw SysError(format("couldn't change to directory of ‘%1%’") % socketPath);
-    Path socketPathRel = "./" + baseNameOf(socketPath);
-
-    struct sockaddr_un addr;
-    addr.sun_family = AF_UNIX;
-    if (socketPathRel.size() >= sizeof(addr.sun_path))
-        throw Error(format("socket path `%1%' is too long") % socketPathRel);
-    using namespace std;
-    strcpy(addr.sun_path, socketPathRel.c_str());
-
-    if (connect(fdSocket, (struct sockaddr *) &addr, sizeof(addr)) == -1)
-        throw SysError(format("cannot connect to daemon at `%1%'") % socketPath);
-
-    if (fchdir(fdPrevDir) == -1)
-        throw SysError("couldn't change back to previous directory");
-}
-
-
-RemoteStore::~RemoteStore()
-{
-    try {
-        to.flush();
-        fdSocket.close();
-    } catch (...) {
-        ignoreException();
-    }
-}
-
-
-void RemoteStore::setOptions()
-{
-    writeInt(wopSetOptions, to);
-
-    writeInt(settings.keepFailed, to);
-    writeInt(settings.keepGoing, to);
-    writeInt(settings.tryFallback, to);
-    writeInt(verbosity, to);
-    writeInt(settings.maxBuildJobs, to);
-    writeInt(settings.maxSilentTime, to);
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 2)
-        writeInt(settings.useBuildHook, to);
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 4) {
-        writeInt(settings.buildVerbosity, to);
-        writeInt(logType, to);
-        writeInt(settings.printBuildTrace, to);
-    }
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 6)
-        writeInt(settings.buildCores, to);
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 10)
-        writeInt(settings.useSubstitutes, to);
-
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 12) {
-        Settings::SettingsMap overrides = settings.getOverrides();
-        writeInt(overrides.size(), to);
-        foreach (Settings::SettingsMap::iterator, i, overrides) {
-            writeString(i->first, to);
-            writeString(i->second, to);
-        }
-    }
-
-    processStderr();
-}
-
-
-bool RemoteStore::isValidPath(const Path & path)
-{
-    openConnection();
-    writeInt(wopIsValidPath, to);
-    writeString(path, to);
-    processStderr();
-    unsigned int reply = readInt(from);
-    return reply != 0;
-}
-
-
-PathSet RemoteStore::queryValidPaths(const PathSet & paths)
-{
-    openConnection();
-    if (GET_PROTOCOL_MINOR(daemonVersion) < 12) {
-        PathSet res;
-        foreach (PathSet::const_iterator, i, paths)
-            if (isValidPath(*i)) res.insert(*i);
-        return res;
-    } else {
-        writeInt(wopQueryValidPaths, to);
-        writeStrings(paths, to);
-        processStderr();
-        return readStorePaths<PathSet>(from);
-    }
-}
-
-
-PathSet RemoteStore::queryAllValidPaths()
-{
-    openConnection();
-    writeInt(wopQueryAllValidPaths, to);
-    processStderr();
-    return readStorePaths<PathSet>(from);
-}
-
-
-PathSet RemoteStore::querySubstitutablePaths(const PathSet & paths)
-{
-    openConnection();
-    if (GET_PROTOCOL_MINOR(daemonVersion) < 12) {
-        PathSet res;
-        foreach (PathSet::const_iterator, i, paths) {
-            writeInt(wopHasSubstitutes, to);
-            writeString(*i, to);
-            processStderr();
-            if (readInt(from)) res.insert(*i);
-        }
-        return res;
-    } else {
-        writeInt(wopQuerySubstitutablePaths, to);
-        writeStrings(paths, to);
-        processStderr();
-        return readStorePaths<PathSet>(from);
-    }
-}
-
-
-void RemoteStore::querySubstitutablePathInfos(const PathSet & paths,
-    SubstitutablePathInfos & infos)
-{
-    if (paths.empty()) return;
-
-    openConnection();
-
-    if (GET_PROTOCOL_MINOR(daemonVersion) < 3) return;
-
-    if (GET_PROTOCOL_MINOR(daemonVersion) < 12) {
-
-        foreach (PathSet::const_iterator, i, paths) {
-            SubstitutablePathInfo info;
-            writeInt(wopQuerySubstitutablePathInfo, to);
-            writeString(*i, to);
-            processStderr();
-            unsigned int reply = readInt(from);
-            if (reply == 0) continue;
-            info.deriver = readString(from);
-            if (info.deriver != "") assertStorePath(info.deriver);
-            info.references = readStorePaths<PathSet>(from);
-            info.downloadSize = readLongLong(from);
-            info.narSize = GET_PROTOCOL_MINOR(daemonVersion) >= 7 ? readLongLong(from) : 0;
-            infos[*i] = info;
-        }
-
-    } else {
-
-        writeInt(wopQuerySubstitutablePathInfos, to);
-        writeStrings(paths, to);
-        processStderr();
-        unsigned int count = readInt(from);
-        for (unsigned int n = 0; n < count; n++) {
-            Path path = readStorePath(from);
-            SubstitutablePathInfo & info(infos[path]);
-            info.deriver = readString(from);
-            if (info.deriver != "") assertStorePath(info.deriver);
-            info.references = readStorePaths<PathSet>(from);
-            info.downloadSize = readLongLong(from);
-            info.narSize = readLongLong(from);
-        }
-
-    }
-}
-
-
-ValidPathInfo RemoteStore::queryPathInfo(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryPathInfo, to);
-    writeString(path, to);
-    processStderr();
-    ValidPathInfo info;
-    info.path = path;
-    info.deriver = readString(from);
-    if (info.deriver != "") assertStorePath(info.deriver);
-    info.hash = parseHash(htSHA256, readString(from));
-    info.references = readStorePaths<PathSet>(from);
-    info.registrationTime = readInt(from);
-    info.narSize = readLongLong(from);
-    return info;
-}
-
-
-Hash RemoteStore::queryPathHash(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryPathHash, to);
-    writeString(path, to);
-    processStderr();
-    string hash = readString(from);
-    return parseHash(htSHA256, hash);
-}
-
-
-void RemoteStore::queryReferences(const Path & path,
-    PathSet & references)
-{
-    openConnection();
-    writeInt(wopQueryReferences, to);
-    writeString(path, to);
-    processStderr();
-    PathSet references2 = readStorePaths<PathSet>(from);
-    references.insert(references2.begin(), references2.end());
-}
-
-
-void RemoteStore::queryReferrers(const Path & path,
-    PathSet & referrers)
-{
-    openConnection();
-    writeInt(wopQueryReferrers, to);
-    writeString(path, to);
-    processStderr();
-    PathSet referrers2 = readStorePaths<PathSet>(from);
-    referrers.insert(referrers2.begin(), referrers2.end());
-}
-
-
-Path RemoteStore::queryDeriver(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryDeriver, to);
-    writeString(path, to);
-    processStderr();
-    Path drvPath = readString(from);
-    if (drvPath != "") assertStorePath(drvPath);
-    return drvPath;
-}
-
-
-PathSet RemoteStore::queryValidDerivers(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryValidDerivers, to);
-    writeString(path, to);
-    processStderr();
-    return readStorePaths<PathSet>(from);
-}
-
-
-PathSet RemoteStore::queryDerivationOutputs(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryDerivationOutputs, to);
-    writeString(path, to);
-    processStderr();
-    return readStorePaths<PathSet>(from);
-}
-
-
-PathSet RemoteStore::queryDerivationOutputNames(const Path & path)
-{
-    openConnection();
-    writeInt(wopQueryDerivationOutputNames, to);
-    writeString(path, to);
-    processStderr();
-    return readStrings<PathSet>(from);
-}
-
-
-Path RemoteStore::queryPathFromHashPart(const string & hashPart)
-{
-    openConnection();
-    writeInt(wopQueryPathFromHashPart, to);
-    writeString(hashPart, to);
-    processStderr();
-    Path path = readString(from);
-    if (!path.empty()) assertStorePath(path);
-    return path;
-}
-
-
-Path RemoteStore::addToStore(const string & name, const Path & _srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, bool repair)
-{
-    if (repair) throw Error("repairing is not supported when building through the Nix daemon");
-
-    openConnection();
-
-    Path srcPath(absPath(_srcPath));
-
-    writeInt(wopAddToStore, to);
-    writeString(name, to);
-    /* backwards compatibility hack */
-    writeInt((hashAlgo == htSHA256 && recursive) ? 0 : 1, to);
-    writeInt(recursive ? 1 : 0, to);
-    writeString(printHashType(hashAlgo), to);
-
-    try {
-        to.written = 0;
-        to.warn = true;
-        dumpPath(srcPath, to, filter);
-        to.warn = false;
-        processStderr();
-    } catch (SysError & e) {
-        /* Daemon closed while we were sending the path. Probably OOM
-           or I/O error. */
-        if (e.errNo == EPIPE)
-            try {
-                processStderr();
-            } catch (EndOfFile & e) { }
-        throw;
-    }
-
-    return readStorePath(from);
-}
-
-
-Path RemoteStore::addTextToStore(const string & name, const string & s,
-    const PathSet & references, bool repair)
-{
-    if (repair) throw Error("repairing is not supported when building through the Nix daemon");
-
-    openConnection();
-    writeInt(wopAddTextToStore, to);
-    writeString(name, to);
-    writeString(s, to);
-    writeStrings(references, to);
-
-    processStderr();
-    return readStorePath(from);
-}
-
-
-void RemoteStore::exportPath(const Path & path, bool sign,
-    Sink & sink)
-{
-    openConnection();
-    writeInt(wopExportPath, to);
-    writeString(path, to);
-    writeInt(sign ? 1 : 0, to);
-    processStderr(&sink); /* sink receives the actual data */
-    readInt(from);
-}
-
-
-Paths RemoteStore::importPaths(bool requireSignature, Source & source)
-{
-    openConnection();
-    writeInt(wopImportPaths, to);
-    /* We ignore requireSignature, since the worker forces it to true
-       anyway. */
-    processStderr(0, &source);
-    return readStorePaths<Paths>(from);
-}
-
-
-void RemoteStore::buildPaths(const PathSet & drvPaths, BuildMode buildMode)
-{
-    openConnection();
-    writeInt(wopBuildPaths, to);
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 13) {
-        writeStrings(drvPaths, to);
-        if (GET_PROTOCOL_MINOR(daemonVersion) >= 15) {
-            writeInt(buildMode, to);
-        }
-        /* Old daemons did not take a 'buildMode' parameter, so we need to
-           validate it here on the client side.  */
-        else if (buildMode != bmNormal) throw Error("repairing or checking \
-is not supported when building through the Nix daemon");
-    }
-    else {
-        /* For backwards compatibility with old daemons, strip output
-           identifiers. */
-        PathSet drvPaths2;
-        foreach (PathSet::const_iterator, i, drvPaths)
-            drvPaths2.insert(string(*i, 0, i->find('!')));
-        writeStrings(drvPaths2, to);
-    }
-    processStderr();
-    readInt(from);
-}
-
-
-void RemoteStore::ensurePath(const Path & path)
-{
-    openConnection();
-    writeInt(wopEnsurePath, to);
-    writeString(path, to);
-    processStderr();
-    readInt(from);
-}
-
-
-void RemoteStore::addTempRoot(const Path & path)
-{
-    openConnection();
-    writeInt(wopAddTempRoot, to);
-    writeString(path, to);
-    processStderr();
-    readInt(from);
-}
-
-
-void RemoteStore::addIndirectRoot(const Path & path)
-{
-    openConnection();
-    writeInt(wopAddIndirectRoot, to);
-    writeString(path, to);
-    processStderr();
-    readInt(from);
-}
-
-
-void RemoteStore::syncWithGC()
-{
-    openConnection();
-    writeInt(wopSyncWithGC, to);
-    processStderr();
-    readInt(from);
-}
-
-
-Roots RemoteStore::findRoots()
-{
-    openConnection();
-    writeInt(wopFindRoots, to);
-    processStderr();
-    unsigned int count = readInt(from);
-    Roots result;
-    while (count--) {
-        Path link = readString(from);
-        Path target = readStorePath(from);
-        result[link] = target;
-    }
-    return result;
-}
-
-
-void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results)
-{
-    openConnection(false);
-
-    writeInt(wopCollectGarbage, to);
-    writeInt(options.action, to);
-    writeStrings(options.pathsToDelete, to);
-    writeInt(options.ignoreLiveness, to);
-    writeLongLong(options.maxFreed, to);
-    writeInt(0, to);
-    if (GET_PROTOCOL_MINOR(daemonVersion) >= 5) {
-        /* removed options */
-        writeInt(0, to);
-        writeInt(0, to);
-    }
-
-    processStderr();
-
-    results.paths = readStrings<PathSet>(from);
-    results.bytesFreed = readLongLong(from);
-    readLongLong(from); // obsolete
-}
-
-
-PathSet RemoteStore::queryFailedPaths()
-{
-    openConnection();
-    writeInt(wopQueryFailedPaths, to);
-    processStderr();
-    return readStorePaths<PathSet>(from);
-}
-
-
-void RemoteStore::clearFailedPaths(const PathSet & paths)
-{
-    openConnection();
-    writeInt(wopClearFailedPaths, to);
-    writeStrings(paths, to);
-    processStderr();
-    readInt(from);
-}
-
-void RemoteStore::optimiseStore()
-{
-    openConnection();
-    writeInt(wopOptimiseStore, to);
-    processStderr();
-    readInt(from);
-}
-
-bool RemoteStore::verifyStore(bool checkContents, bool repair)
-{
-    openConnection();
-    writeInt(wopVerifyStore, to);
-    writeInt(checkContents, to);
-    writeInt(repair, to);
-    processStderr();
-    return readInt(from) != 0;
-}
-
-void RemoteStore::processStderr(Sink * sink, Source * source)
-{
-    to.flush();
-    unsigned int msg;
-    while ((msg = readInt(from)) == STDERR_NEXT
-        || msg == STDERR_READ || msg == STDERR_WRITE) {
-        if (msg == STDERR_WRITE) {
-            string s = readString(from);
-            if (!sink) throw Error("no sink");
-            (*sink)((const unsigned char *) s.data(), s.size());
-        }
-        else if (msg == STDERR_READ) {
-            if (!source) throw Error("no source");
-            size_t len = readInt(from);
-            unsigned char * buf = new unsigned char[len];
-            AutoDeleteArray<unsigned char> d(buf);
-            writeString(buf, source->read(buf, len), to);
-            to.flush();
-        }
-        else {
-            string s = readString(from);
-            writeToStderr(s);
-        }
-    }
-    if (msg == STDERR_ERROR) {
-        string error = readString(from);
-        unsigned int status = GET_PROTOCOL_MINOR(daemonVersion) >= 8 ? readInt(from) : 1;
-        throw Error(format("%1%") % error, status);
-    }
-    else if (msg != STDERR_LAST)
-        throw Error("protocol error processing standard error");
-}
-
-
-}
diff --git a/nix/libstore/remote-store.hh b/nix/libstore/remote-store.hh
deleted file mode 100644
index 030120db40..0000000000
--- a/nix/libstore/remote-store.hh
+++ /dev/null
@@ -1,106 +0,0 @@
-#pragma once
-
-#include <string>
-
-#include "store-api.hh"
-
-
-namespace nix {
-
-
-class Pipe;
-class Pid;
-struct FdSink;
-struct FdSource;
-
-
-class RemoteStore : public StoreAPI
-{
-public:
-
-    RemoteStore();
-
-    ~RemoteStore();
-
-    /* Implementations of abstract store API methods. */
-
-    bool isValidPath(const Path & path);
-
-    PathSet queryValidPaths(const PathSet & paths);
-
-    PathSet queryAllValidPaths();
-
-    ValidPathInfo queryPathInfo(const Path & path);
-
-    Hash queryPathHash(const Path & path);
-
-    void queryReferences(const Path & path, PathSet & references);
-
-    void queryReferrers(const Path & path, PathSet & referrers);
-
-    Path queryDeriver(const Path & path);
-
-    PathSet queryValidDerivers(const Path & path);
-
-    PathSet queryDerivationOutputs(const Path & path);
-
-    StringSet queryDerivationOutputNames(const Path & path);
-
-    Path queryPathFromHashPart(const string & hashPart);
-
-    PathSet querySubstitutablePaths(const PathSet & paths);
-
-    void querySubstitutablePathInfos(const PathSet & paths,
-        SubstitutablePathInfos & infos);
-
-    Path addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
-        PathFilter & filter = defaultPathFilter, bool repair = false);
-
-    Path addTextToStore(const string & name, const string & s,
-        const PathSet & references, bool repair = false);
-
-    void exportPath(const Path & path, bool sign,
-        Sink & sink);
-
-    Paths importPaths(bool requireSignature, Source & source);
-
-    void buildPaths(const PathSet & paths, BuildMode buildMode);
-
-    void ensurePath(const Path & path);
-
-    void addTempRoot(const Path & path);
-
-    void addIndirectRoot(const Path & path);
-
-    void syncWithGC();
-
-    Roots findRoots();
-
-    void collectGarbage(const GCOptions & options, GCResults & results);
-
-    PathSet queryFailedPaths();
-
-    void clearFailedPaths(const PathSet & paths);
-
-    void optimiseStore();
-
-    bool verifyStore(bool checkContents, bool repair);
-private:
-    AutoCloseFD fdSocket;
-    FdSink to;
-    FdSource from;
-    unsigned int daemonVersion;
-    bool initialised;
-
-    void openConnection(bool reserveSpace = true);
-
-    void processStderr(Sink * sink = 0, Source * source = 0);
-
-    void connectToDaemon();
-
-    void setOptions();
-};
-
-
-}
diff --git a/nix/libstore/store-api.cc b/nix/libstore/store-api.cc
index 0238e5b0b6..30af5f5fed 100644
--- a/nix/libstore/store-api.cc
+++ b/nix/libstore/store-api.cc
@@ -304,13 +304,28 @@ void exportPaths(StoreAPI & store, const Paths & paths,
     writeInt(0, sink);
 }
 
+Path readStorePath(Source & from)
+{
+    Path path = readString(from);
+    assertStorePath(path);
+    return path;
+}
+
+
+template<class T> T readStorePaths(Source & from)
+{
+    T paths = readStrings<T>(from);
+    foreach (typename T::iterator, i, paths) assertStorePath(*i);
+    return paths;
+}
+
+template PathSet readStorePaths(Source & from);
 
 }
 
 
 #include "local-store.hh"
 #include "serialise.hh"
-#include "remote-store.hh"
 
 
 namespace nix {
@@ -321,10 +336,7 @@ std::shared_ptr<StoreAPI> store;
 
 std::shared_ptr<StoreAPI> openStore(bool reserveSpace)
 {
-    if (getEnv("NIX_REMOTE") == "")
-        return std::shared_ptr<StoreAPI>(new LocalStore(reserveSpace));
-    else
-        return std::shared_ptr<StoreAPI>(new RemoteStore());
+    return std::shared_ptr<StoreAPI>(new LocalStore(reserveSpace));
 }
 
 
diff --git a/nix/libstore/store-api.hh b/nix/libstore/store-api.hh
index 9403cbee19..3e982f6dd3 100644
--- a/nix/libstore/store-api.hh
+++ b/nix/libstore/store-api.hh
@@ -106,6 +106,30 @@ typedef list<ValidPathInfo> ValidPathInfos;
 
 enum BuildMode { bmNormal, bmRepair, bmCheck };
 
+struct BuildResult
+{
+    enum Status {
+        Built = 0,
+        Substituted,
+        AlreadyValid,
+        PermanentFailure,
+        InputRejected,
+        OutputRejected,
+        TransientFailure, // possibly transient
+        CachedFailure,
+        TimedOut,
+        MiscFailure,
+        DependencyFailed,
+        LogLimitExceeded,
+        NotDeterministic,
+    } status = MiscFailure;
+    std::string errorMsg;
+    //time_t startTime = 0, stopTime = 0;
+    bool success() {
+        return status == Built || status == Substituted || status == AlreadyValid;
+    }
+};
+
 
 class StoreAPI
 {
diff --git a/nix/nix-daemon/guix-daemon.cc b/nix/nix-daemon/guix-daemon.cc
index 1934487d24..20a0732fcb 100644
--- a/nix/nix-daemon/guix-daemon.cc
+++ b/nix/nix-daemon/guix-daemon.cc
@@ -80,6 +80,7 @@ builds derivations on behalf of its clients.");
 #define GUIX_OPT_NO_BUILD_HOOK 14
 #define GUIX_OPT_GC_KEEP_OUTPUTS 15
 #define GUIX_OPT_GC_KEEP_DERIVATIONS 16
+#define GUIX_OPT_BUILD_ROUNDS 17
 
 static const struct argp_option options[] =
   {
@@ -104,6 +105,8 @@ static const struct argp_option options[] =
       n_("do not use the 'build hook'") },
     { "cache-failures", GUIX_OPT_CACHE_FAILURES, 0, 0,
       n_("cache build failures") },
+    { "rounds", GUIX_OPT_BUILD_ROUNDS, "N", 0,
+      n_("build each derivation N times in a row") },
     { "lose-logs", GUIX_OPT_LOSE_LOGS, 0, 0,
       n_("do not keep build logs") },
     { "disable-log-compression", GUIX_OPT_DISABLE_LOG_COMPRESSION, 0, 0,
@@ -189,6 +192,18 @@ parse_opt (int key, char *arg, struct argp_state *state)
     case GUIX_OPT_CACHE_FAILURES:
       settings.cacheFailure = true;
       break;
+    case GUIX_OPT_BUILD_ROUNDS:
+      {
+	char *end;
+	unsigned long n = strtoul (arg, &end, 10);
+	if (end != arg + strlen (arg))
+	  {
+	    fprintf (stderr, _("error: %s: invalid number of rounds\n"), arg);
+	    exit (EXIT_FAILURE);
+	  }
+	settings.set ("build-repeat", std::to_string (std::max (0UL, n - 1)));
+	break;
+      }
     case GUIX_OPT_IMPERSONATE_LINUX_26:
       settings.impersonateLinux26 = true;
       break;