Merge remote-tracking branch 'origin/master' into lazy-trees

.version

@@ -1 +1 @@
-2.10.0
+2.12.0

doc/manual/src/SUMMARY.md.in

@@ -73,6 +73,7 @@
   - [CLI guideline](contributing/cli-guideline.md)
 - [Release Notes](release-notes/release-notes.md)
   - [Release X.Y (202?-??-??)](release-notes/rl-next.md)
+  - [Release 2.11 (2022-08-25)](release-notes/rl-2.11.md)
   - [Release 2.10 (2022-07-11)](release-notes/rl-2.10.md)
   - [Release 2.9 (2022-05-30)](release-notes/rl-2.9.md)
   - [Release 2.8 (2022-04-19)](release-notes/rl-2.8.md)

doc/manual/src/language/index.md

@@ -1,13 +1,33 @@
 # Nix Language
 
-The Nix language is a pure, lazy, functional language. Purity
-means that operations in the language don't have side-effects (for
-instance, there is no variable assignment). Laziness means that
-arguments to functions are evaluated only when they are needed.
-Functional means that functions are “normal” values that can be passed
-around and manipulated in interesting ways. The language is not a
-full-featured, general purpose language. Its main job is to describe
-packages, compositions of packages, and the variability within packages.
+The Nix language is
 
-This section presents the various features of the language.
+- *domain-specific*
+
+  It only exists for the Nix package manager:
+  to describe packages and configurations as well as their variants and compositions.
+  It is not intended for general purpose use.
+
+- *declarative*
+
+  There is no notion of executing sequential steps.
+  Dependencies between operations are established only through data.
+
+- *pure*
+
+  Values cannot change during computation.
+  Functions always produce the same output if their input does not change.
+
+- *functional*
+
+  Functions are like any other value.
+  Functions can be assigned to names, taken as arguments, or returned by functions.
+
+- *lazy*
+
+  Expressions are only evaluated when their value is needed.
+
+- *dynamically typed*
+
+  Type errors are only detected when expressions are evaluated.
 

doc/manual/src/release-notes/rl-2.11.md

@@ -0,0 +1,5 @@
+# Release 2.11 (2022-08-24)
+
+* `nix copy` now copies the store paths in parallel as much as possible (again).
+  This doesn't apply for the `daemon` and `ssh-ng` stores which copy everything
+  in one batch to avoid latencies issues.

docker.nix

@@ -2,6 +2,7 @@
 , lib ? pkgs.lib
 , name ? "nix"
 , tag ? "latest"
+, bundleNixpkgs ? true
 , channelName ? "nixpkgs"
 , channelURL ? "https://nixos.org/channels/nixpkgs-unstable"
 , extraPkgs ? []
@@ -139,10 +140,12 @@ let
   baseSystem =
     let
       nixpkgs = pkgs.path;
-      channel = pkgs.runCommand "channel-nixos" { } ''
+      channel = pkgs.runCommand "channel-nixos" { inherit bundleNixpkgs; } ''
         mkdir $out
-        ln -s ${nixpkgs} $out/nixpkgs
-        echo "[]" > $out/manifest.nix
+        if [ "$bundleNixpkgs" ]; then
+          ln -s ${nixpkgs} $out/nixpkgs
+          echo "[]" > $out/manifest.nix
+        fi
       '';
       rootEnv = pkgs.buildPackages.buildEnv {
         name = "root-profile-env";

scripts/install-darwin-multi-user.sh

@@ -167,7 +167,7 @@ poly_user_shell_get() {
 }
 
 poly_user_shell_set() {
-    _sudo "in order to give $1 a safe home directory" \
+    _sudo "in order to give $1 a safe shell" \
           /usr/bin/dscl . -create "/Users/$1" "UserShell" "$2"
 }
 

scripts/install-multi-user.sh

@@ -348,8 +348,12 @@ _sudo() {
     fi
 }
 
+# Ensure that $TMPDIR exists if defined.
+if [[ -n "${TMPDIR:-}" ]] && [[ ! -d "${TMPDIR:-}" ]]; then
+    mkdir -m 0700 -p "${TMPDIR:-}"
+fi
 
-readonly SCRATCH=$(mktemp -d "${TMPDIR:-/tmp/}tmp.XXXXXXXXXX")
+readonly SCRATCH=$(mktemp -d)
 finish_cleanup() {
     rm -rf "$SCRATCH"
 }

src/libcmd/repl.cc

@@ -35,6 +35,7 @@ extern "C" {
 #include "finally.hh"
 #include "markdown.hh"
 #include "local-fs-store.hh"
+#include "progress-bar.hh"
 
 #if HAVE_BOEHMGC
 #define GC_INCLUDE_NEW
@@ -250,6 +251,10 @@ void NixRepl::mainLoop()
     rl_set_list_possib_func(listPossibleCallback);
 #endif
 
+    /* Stop the progress bar because it interferes with the display of
+       the repl. */
+    stopProgressBar();
+
     std::string input;
 
     while (true) {
@@ -1037,9 +1042,10 @@ void runRepl(
 
 struct CmdRepl : InstallablesCommand
 {
-    CmdRepl(){
+    CmdRepl() {
         evalSettings.pureEval = false;
     }
+
     void prepare()
     {
         if (!settings.isExperimentalFeatureEnabled(Xp::ReplFlake) && !(file) && this->_installables.size() >= 1) {
@@ -1053,12 +1059,15 @@ struct CmdRepl : InstallablesCommand
         }
         installables = InstallablesCommand::load();
     }
+
     std::vector<std::string> files;
+
     Strings getDefaultFlakeAttrPaths() override
     {
         return {""};
     }
-    virtual bool useDefaultInstallables() override
+
+    bool useDefaultInstallables() override
     {
         return file.has_value() or expr.has_value();
     }

src/libexpr/eval-cache.cc

@@ -510,11 +510,6 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
         return nullptr;
         //throw TypeError("'%s' is not an attribute set", getAttrPathStr());
 
-    for (auto & attr : *v.attrs) {
-        if (root->db)
-            root->db->setPlaceholder({cachedValue->first, attr.name});
-    }
-
     auto attr = v.attrs->get(name);
 
     if (!attr) {

src/libexpr/value-to-json.cc

@@ -11,7 +11,7 @@
 namespace nix {
 
 void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const PosIdx pos, JSONPlaceholder & out, PathSet & context)
+    Value & v, const PosIdx pos, JSONPlaceholder & out, PathSet & context, bool copyToStore)
 {
     checkInterrupt();
 
@@ -33,10 +33,13 @@ void printValueAsJSON(EvalState & state, bool strict,
             break;
 
         case nPath:
-            // FIXME: handle accessors
-            out.write(
-                state.store->printStorePath(
-                    state.copyPathToStore(context, v.path())));
+            if (copyToStore)
+                // FIXME: handle accessors
+                out.write(
+                    state.store->printStorePath(
+                        state.copyPathToStore(context, v.path())));
+            else
+                out.write(v.path().path.abs());
             break;
 
         case nNull:
@@ -58,10 +61,10 @@ void printValueAsJSON(EvalState & state, bool strict,
                 for (auto & j : names) {
                     Attr & a(*v.attrs->find(state.symbols.create(j)));
                     auto placeholder(obj.placeholder(j));
-                    printValueAsJSON(state, strict, *a.value, a.pos, placeholder, context);
+                    printValueAsJSON(state, strict, *a.value, a.pos, placeholder, context, copyToStore);
                 }
             } else
-                printValueAsJSON(state, strict, *i->value, i->pos, out, context);
+                printValueAsJSON(state, strict, *i->value, i->pos, out, context, copyToStore);
             break;
         }
 
@@ -69,13 +72,13 @@ void printValueAsJSON(EvalState & state, bool strict,
             auto list(out.list());
             for (auto elem : v.listItems()) {
                 auto placeholder(list.placeholder());
-                printValueAsJSON(state, strict, *elem, pos, placeholder, context);
+                printValueAsJSON(state, strict, *elem, pos, placeholder, context, copyToStore);
             }
             break;
         }
 
         case nExternal:
-            v.external->printValueAsJSON(state, strict, out, context);
+            v.external->printValueAsJSON(state, strict, out, context, copyToStore);
             break;
 
         case nFloat:
@@ -95,14 +98,14 @@ void printValueAsJSON(EvalState & state, bool strict,
 }
 
 void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const PosIdx pos, std::ostream & str, PathSet & context)
+    Value & v, const PosIdx pos, std::ostream & str, PathSet & context, bool copyToStore)
 {
     JSONPlaceholder out(str);
-    printValueAsJSON(state, strict, v, pos, out, context);
+    printValueAsJSON(state, strict, v, pos, out, context, copyToStore);
 }
 
 void ExternalValueBase::printValueAsJSON(EvalState & state, bool strict,
-    JSONPlaceholder & out, PathSet & context) const
+    JSONPlaceholder & out, PathSet & context, bool copyToStore) const
 {
     state.debugThrowLastTrace(TypeError("cannot convert %1% to JSON", showType()));
 }

src/libexpr/value-to-json.hh

@@ -11,9 +11,9 @@ namespace nix {
 class JSONPlaceholder;
 
 void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const PosIdx pos, JSONPlaceholder & out, PathSet & context);
+    Value & v, const PosIdx pos, JSONPlaceholder & out, PathSet & context, bool copyToStore = true);
 
 void printValueAsJSON(EvalState & state, bool strict,
-    Value & v, const PosIdx pos, std::ostream & str, PathSet & context);
+    Value & v, const PosIdx pos, std::ostream & str, PathSet & context, bool copyToStore = true);
 
 }

src/libexpr/value.hh

@@ -100,7 +100,7 @@ class ExternalValueBase
 
     /* Print the value as JSON. Defaults to unconvertable, i.e. throws an error */
     virtual void printValueAsJSON(EvalState & state, bool strict,
-        JSONPlaceholder & out, PathSet & context) const;
+        JSONPlaceholder & out, PathSet & context, bool copyToStore = true) const;
 
     /* Print the value as XML. Defaults to unevaluated */
     virtual void printValueAsXML(EvalState & state, bool strict, bool location,

src/libmain/loggers.cc

@@ -30,8 +30,11 @@ Logger * makeDefaultLogger() {
         return makeJSONLogger(*makeSimpleLogger(true));
     case LogFormat::bar:
         return makeProgressBar();
-    case LogFormat::barWithLogs:
-        return makeProgressBar(true);
+    case LogFormat::barWithLogs: {
+        auto logger = makeProgressBar();
+        logger->setPrintBuildLogs(true);
+        return logger;
+    }
     default:
         abort();
     }

src/libmain/progress-bar.cc

@@ -81,14 +81,13 @@ private:
 
     std::condition_variable quitCV, updateCV;
 
-    bool printBuildLogs;
+    bool printBuildLogs = false;
     bool isTTY;
 
 public:
 
-    ProgressBar(bool printBuildLogs, bool isTTY)
-        : printBuildLogs(printBuildLogs)
-        , isTTY(isTTY)
+    ProgressBar(bool isTTY)
+        : isTTY(isTTY)
     {
         state_.lock()->active = isTTY;
         updateThread = std::thread([&]() {
@@ -503,19 +502,21 @@ public:
         draw(*state);
         return s[0];
     }
+
+    virtual void setPrintBuildLogs(bool printBuildLogs)
+    {
+        this->printBuildLogs = printBuildLogs;
+    }
 };
 
-Logger * makeProgressBar(bool printBuildLogs)
+Logger * makeProgressBar()
 {
-    return new ProgressBar(
-        printBuildLogs,
-        shouldANSI()
-    );
+    return new ProgressBar(shouldANSI());
 }
 
-void startProgressBar(bool printBuildLogs)
+void startProgressBar()
 {
-    logger = makeProgressBar(printBuildLogs);
+    logger = makeProgressBar();
 }
 
 void stopProgressBar()

src/libmain/progress-bar.hh

@@ -4,9 +4,9 @@
 
 namespace nix {
 
-Logger * makeProgressBar(bool printBuildLogs = false);
+Logger * makeProgressBar();
 
-void startProgressBar(bool printBuildLogs = false);
+void startProgressBar();
 
 void stopProgressBar();
 

src/libstore/filetransfer.cc

@@ -308,6 +308,9 @@ struct curlFileTransfer : public FileTransfer
 
             curl_easy_setopt(req, CURLOPT_HTTPHEADER, requestHeaders);
 
+            if (settings.downloadSpeed.get() > 0)
+                curl_easy_setopt(req, CURLOPT_MAX_RECV_SPEED_LARGE, (curl_off_t) (settings.downloadSpeed.get() * 1024));
+
             if (request.head)
                 curl_easy_setopt(req, CURLOPT_NOBODY, 1);
 

src/libstore/globals.hh

@@ -746,6 +746,13 @@ public:
               /nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23`.
         )"};
 
+    Setting<unsigned int> downloadSpeed {
+        this, 0, "download-speed",
+        R"(
+          Specify the maximum transfer rate in kilobytes per second you want
+          Nix to use for downloads.
+        )"};
+
     Setting<std::string> netrcFile{
         this, fmt("%s/%s", nixConfDir, "netrc"), "netrc-file",
         R"(

src/libstore/remote-store.cc

@@ -671,6 +671,23 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
 }
 
 
+void RemoteStore::addMultipleToStore(
+    PathsSource & pathsToCopy,
+    Activity & act,
+    RepairFlag repair,
+    CheckSigsFlag checkSigs)
+{
+    auto source = sinkToSource([&](Sink & sink) {
+        sink << pathsToCopy.size();
+        for (auto & [pathInfo, pathSource] : pathsToCopy) {
+            pathInfo.write(sink, *this, 16);
+            pathSource->drainInto(sink);
+        }
+    });
+
+    addMultipleToStore(*source, repair, checkSigs);
+}
+
 void RemoteStore::addMultipleToStore(
     Source & source,
     RepairFlag repair,

src/libstore/remote-store.hh

@@ -88,6 +88,12 @@ public:
         RepairFlag repair,
         CheckSigsFlag checkSigs) override;
 
+    void addMultipleToStore(
+        PathsSource & pathsToCopy,
+        Activity & act,
+        RepairFlag repair,
+        CheckSigsFlag checkSigs) override;
+
     StorePath addTextToStore(
         std::string_view name,
         std::string_view s,

src/libstore/store-api.cc

@@ -262,6 +262,84 @@ StorePath Store::addToStore(
     return addToStoreFromDump(*source, name, method, hashAlgo, repair, references);
 }
 
+void Store::addMultipleToStore(
+    PathsSource & pathsToCopy,
+    Activity & act,
+    RepairFlag repair,
+    CheckSigsFlag checkSigs)
+{
+    std::atomic<size_t> nrDone{0};
+    std::atomic<size_t> nrFailed{0};
+    std::atomic<uint64_t> bytesExpected{0};
+    std::atomic<uint64_t> nrRunning{0};
+
+    using PathWithInfo = std::pair<ValidPathInfo, std::unique_ptr<Source>>;
+
+    std::map<StorePath, PathWithInfo *> infosMap;
+    StorePathSet storePathsToAdd;
+    for (auto & thingToAdd : pathsToCopy) {
+        infosMap.insert_or_assign(thingToAdd.first.path, &thingToAdd);
+        storePathsToAdd.insert(thingToAdd.first.path);
+    }
+
+    auto showProgress = [&]() {
+        act.progress(nrDone, pathsToCopy.size(), nrRunning, nrFailed);
+    };
+
+    ThreadPool pool;
+
+    processGraph<StorePath>(pool,
+        storePathsToAdd,
+
+        [&](const StorePath & path) {
+
+            auto & [info, _] = *infosMap.at(path);
+
+            if (isValidPath(info.path)) {
+                nrDone++;
+                showProgress();
+                return StorePathSet();
+            }
+
+            bytesExpected += info.narSize;
+            act.setExpected(actCopyPath, bytesExpected);
+
+            return info.references;
+        },
+
+        [&](const StorePath & path) {
+            checkInterrupt();
+
+            auto & [info_, source_] = *infosMap.at(path);
+            auto info = info_;
+            info.ultimate = false;
+
+            /* Make sure that the Source object is destroyed when
+               we're done. In particular, a SinkToSource object must
+               be destroyed to ensure that the destructors on its
+               stack frame are run; this includes
+               LegacySSHStore::narFromPath()'s connection lock. */
+            auto source = std::move(source_);
+
+            if (!isValidPath(info.path)) {
+                MaintainCount<decltype(nrRunning)> mc(nrRunning);
+                showProgress();
+                try {
+                    addToStore(info, *source, repair, checkSigs);
+                } catch (Error & e) {
+                    nrFailed++;
+                    if (!settings.keepGoing)
+                        throw e;
+                    printMsg(lvlError, "could not copy %s: %s", printStorePath(path), e.what());
+                    showProgress();
+                    return;
+                }
+            }
+
+            nrDone++;
+            showProgress();
+        });
+}
 
 void Store::addMultipleToStore(
     Source & source,
@@ -996,113 +1074,61 @@ std::map<StorePath, StorePath> copyPaths(
     for (auto & path : storePaths)
         if (!valid.count(path)) missing.insert(path);
 
+    Activity act(*logger, lvlInfo, actCopyPaths, fmt("copying %d paths", missing.size()));
+
+    // In the general case, `addMultipleToStore` requires a sorted list of
+    // store paths to add, so sort them right now
+    auto sortedMissing = srcStore.topoSortPaths(missing);
+    std::reverse(sortedMissing.begin(), sortedMissing.end());
+
     std::map<StorePath, StorePath> pathsMap;
     for (auto & path : storePaths)
         pathsMap.insert_or_assign(path, path);
 
-    Activity act(*logger, lvlInfo, actCopyPaths, fmt("copying %d paths", missing.size()));
+    Store::PathsSource pathsToCopy;
 
-    auto sorted = srcStore.topoSortPaths(missing);
-    std::reverse(sorted.begin(), sorted.end());
+    auto computeStorePathForDst = [&](const ValidPathInfo & currentPathInfo) -> StorePath {
+        auto storePathForSrc = currentPathInfo.path;
+        auto storePathForDst = storePathForSrc;
+        if (currentPathInfo.ca && currentPathInfo.references.empty()) {
+            storePathForDst = dstStore.makeFixedOutputPathFromCA(storePathForSrc.name(), *currentPathInfo.ca);
+            if (dstStore.storeDir == srcStore.storeDir)
+                assert(storePathForDst == storePathForSrc);
+            if (storePathForDst != storePathForSrc)
+                debug("replaced path '%s' to '%s' for substituter '%s'",
+                        srcStore.printStorePath(storePathForSrc),
+                        dstStore.printStorePath(storePathForDst),
+                        dstStore.getUri());
+        }
+        return storePathForDst;
+    };
 
-    auto source = sinkToSource([&](Sink & sink) {
-        sink << sorted.size();
-        for (auto & storePath : sorted) {
+    for (auto & missingPath : sortedMissing) {
+        auto info = srcStore.queryPathInfo(missingPath);
+
+        auto storePathForDst = computeStorePathForDst(*info);
+        pathsMap.insert_or_assign(missingPath, storePathForDst);
+
+        ValidPathInfo infoForDst = *info;
+        infoForDst.path = storePathForDst;
+
+        auto source = sinkToSource([&](Sink & sink) {
+            // We can reasonably assume that the copy will happen whenever we
+            // read the path, so log something about that at that point
             auto srcUri = srcStore.getUri();
             auto dstUri = dstStore.getUri();
-            auto storePathS = srcStore.printStorePath(storePath);
+            auto storePathS = srcStore.printStorePath(missingPath);
             Activity act(*logger, lvlInfo, actCopyPath,
                 makeCopyPathMessage(srcUri, dstUri, storePathS),
                 {storePathS, srcUri, dstUri});
             PushActivity pact(act.id);
 
-            auto info = srcStore.queryPathInfo(storePath);
-            info->write(sink, srcStore, 16);
-            srcStore.narFromPath(storePath, sink);
-        }
-    });
-
-    dstStore.addMultipleToStore(*source, repair, checkSigs);
-
-    #if 0
-    std::atomic<size_t> nrDone{0};
-    std::atomic<size_t> nrFailed{0};
-    std::atomic<uint64_t> bytesExpected{0};
-    std::atomic<uint64_t> nrRunning{0};
-
-    auto showProgress = [&]() {
-        act.progress(nrDone, missing.size(), nrRunning, nrFailed);
-    };
-
-    ThreadPool pool;
-
-    processGraph<StorePath>(pool,
-        StorePathSet(missing.begin(), missing.end()),
-
-        [&](const StorePath & storePath) {
-            auto info = srcStore.queryPathInfo(storePath);
-            auto storePathForDst = storePath;
-            if (info->ca && info->references.empty()) {
-                storePathForDst = dstStore.makeFixedOutputPathFromCA(storePath.name(), *info->ca);
-                if (dstStore.storeDir == srcStore.storeDir)
-                    assert(storePathForDst == storePath);
-                if (storePathForDst != storePath)
-                    debug("replaced path '%s' to '%s' for substituter '%s'",
-                        srcStore.printStorePath(storePath),
-                        dstStore.printStorePath(storePathForDst),
-                        dstStore.getUri());
-            }
-            pathsMap.insert_or_assign(storePath, storePathForDst);
-
-            if (dstStore.isValidPath(storePath)) {
-                nrDone++;
-                showProgress();
-                return StorePathSet();
-            }
-
-            bytesExpected += info->narSize;
-            act.setExpected(actCopyPath, bytesExpected);
-
-            return info->references;
-        },
-
-        [&](const StorePath & storePath) {
-            checkInterrupt();
-
-            auto info = srcStore.queryPathInfo(storePath);
-
-            auto storePathForDst = storePath;
-            if (info->ca && info->references.empty()) {
-                storePathForDst = dstStore.makeFixedOutputPathFromCA(storePath.name(), *info->ca);
-                if (dstStore.storeDir == srcStore.storeDir)
-                    assert(storePathForDst == storePath);
-                if (storePathForDst != storePath)
-                    debug("replaced path '%s' to '%s' for substituter '%s'",
-                        srcStore.printStorePath(storePath),
-                        dstStore.printStorePath(storePathForDst),
-                        dstStore.getUri());
-            }
-            pathsMap.insert_or_assign(storePath, storePathForDst);
-
-            if (!dstStore.isValidPath(storePathForDst)) {
-                MaintainCount<decltype(nrRunning)> mc(nrRunning);
-                showProgress();
-                try {
-                    copyStorePath(srcStore, dstStore, storePath, repair, checkSigs);
-                } catch (Error &e) {
-                    nrFailed++;
-                    if (!settings.keepGoing)
-                        throw e;
-                    printMsg(lvlError, "could not copy %s: %s", dstStore.printStorePath(storePath), e.what());
-                    showProgress();
-                    return;
-                }
-            }
-
-            nrDone++;
-            showProgress();
+            srcStore.narFromPath(missingPath, sink);
         });
-    #endif
+        pathsToCopy.push_back(std::pair{infoForDst, std::move(source)});
+    }
+
+    dstStore.addMultipleToStore(pathsToCopy, act, repair, checkSigs);
 
     return pathsMap;
 }

src/libstore/store-api.hh

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "nar-info.hh"
 #include "realisation.hh"
 #include "path.hh"
 #include "derived-path.hh"
@@ -361,12 +362,22 @@ public:
     virtual void addToStore(const ValidPathInfo & info, Source & narSource,
         RepairFlag repair = NoRepair, CheckSigsFlag checkSigs = CheckSigs) = 0;
 
+    // A list of paths infos along with a source providing the content of the
+    // associated store path
+    using PathsSource = std::vector<std::pair<ValidPathInfo, std::unique_ptr<Source>>>;
+
     /* Import multiple paths into the store. */
     virtual void addMultipleToStore(
         Source & source,
         RepairFlag repair = NoRepair,
         CheckSigsFlag checkSigs = CheckSigs);
 
+    virtual void addMultipleToStore(
+        PathsSource & pathsToCopy,
+        Activity & act,
+        RepairFlag repair = NoRepair,
+        CheckSigsFlag checkSigs = CheckSigs);
+
     /* Copy the contents of a path to the store and register the
        validity the resulting path.  The resulting path is returned.
        The function object `filter' can be used to exclude files (see

src/libutil/json.cc

@@ -193,7 +193,11 @@ JSONObject JSONPlaceholder::object()
 
 JSONPlaceholder::~JSONPlaceholder()
 {
-    assert(!first || std::uncaught_exceptions());
+    if (first) {
+        assert(std::uncaught_exceptions());
+        if (state->stack != 0)
+            write(nullptr);
+    }
 }
 
 }

src/libutil/logging.hh

@@ -111,6 +111,9 @@ public:
 
     virtual std::optional<char> ask(std::string_view s)
     { return {}; }
+
+    virtual void setPrintBuildLogs(bool printBuildLogs)
+    { }
 };
 
 ActivityId getCurActivity();

src/nix-build/nix-build.cc

@@ -406,7 +406,7 @@ static void main_nix_build(int argc, char * * argv)
                 auto bashDrv = drv->requireDrvPath();
                 pathsToBuild.push_back(DerivedPath::Built {
                     .drvPath = bashDrv,
-                    .outputs = {},
+                    .outputs = {"out"},
                 });
                 pathsToCopy.insert(bashDrv);
                 shellDrv = bashDrv;

src/nix-env/nix-env.cc

@@ -942,12 +942,12 @@ static void queryJSON(Globals & globals, std::vector<DrvInfo> & elems, bool prin
                 JSONObject metaObj = pkgObj.object("meta");
                 StringSet metaNames = i.queryMetaNames();
                 for (auto & j : metaNames) {
-                    auto placeholder = metaObj.placeholder(j);
                     Value * v = i.queryMeta(j);
                     if (!v) {
                         printError("derivation '%s' has invalid meta attribute '%s'", i.queryName(), j);
-                        placeholder.write(nullptr);
+                        metaObj.attr(j, nullptr);
                     } else {
+                        auto placeholder = metaObj.placeholder(j);
                         PathSet context;
                         printValueAsJSON(*globals.state, true, *v, noPos, placeholder, context);
                     }

src/nix-instantiate/nix-instantiate.cc

@@ -52,9 +52,10 @@ void processExpr(EvalState & state, const Strings & attrPaths,
                 state.autoCallFunction(autoArgs, v, vRes);
             if (output == okXML)
                 printValueAsXML(state, strict, location, vRes, std::cout, context, noPos);
-            else if (output == okJSON)
+            else if (output == okJSON) {
                 printValueAsJSON(state, strict, vRes, v.determinePos(noPos), std::cout, context);
-            else {
+                std::cout << std::endl;
+            } else {
                 if (strict) state.forceValueDeep(vRes);
                 vRes.print(state.symbols, std::cout);
                 std::cout << std::endl;

src/nix-store/nix-store.cc

@@ -922,7 +922,7 @@ static void opServe(Strings opFlags, Strings opArgs)
 
                 if (GET_PROTOCOL_MINOR(clientVersion) >= 3)
                     out << status.timesBuilt << status.isNonDeterministic << status.startTime << status.stopTime;
-                if (GET_PROTOCOL_MINOR(clientVersion >= 6)) {
+                if (GET_PROTOCOL_MINOR(clientVersion) >= 6) {
                     worker_proto::write(*store, out, status.builtOutputs);
                 }
 

src/nix/eval.cc

@@ -116,7 +116,8 @@ struct CmdEval : MixJSON, InstallableCommand
 
         else if (json) {
             JSONPlaceholder jsonOut(std::cout);
-            printValueAsJSON(*state, true, *v, pos, jsonOut, context);
+            printValueAsJSON(*state, true, *v, pos, jsonOut, context, false);
+            std::cout << std::endl;
         }
 
         else {

src/nix/get-env.sh

@@ -43,6 +43,7 @@ __dumpEnv() {
         local __var_name="${BASH_REMATCH[2]}"
 
         if [[ $__var_name =~ ^BASH_ || \
+              $__var_name =~ ^COMP_ || \
               $__var_name = _ || \
               $__var_name = DIRSTACK || \
               $__var_name = EUID || \
@@ -54,7 +55,9 @@ __dumpEnv() {
               $__var_name = PWD || \
               $__var_name = RANDOM || \
               $__var_name = SHLVL || \
-              $__var_name = SECONDS \
+              $__var_name = SECONDS || \
+              $__var_name = EPOCHREALTIME || \
+              $__var_name = EPOCHSECONDS \
             ]]; then continue; fi
 
         if [[ -z $__first ]]; then printf ',\n'; else __first=; fi

src/nix/main.cc

@@ -82,7 +82,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
             .shortName = 'L',
             .description = "Print full build logs on standard error.",
             .category = loggingCategory,
-            .handler = {[&]() {setLogFormat(LogFormat::barWithLogs); }},
+            .handler = {[&]() { logger->setPrintBuildLogs(true); }},
         });
 
         addFlag({

src/nix/profile.md

@@ -11,7 +11,7 @@ them to be rolled back easily.
 
 The default profile used by `nix profile` is `$HOME/.nix-profile`,
 which, if it does not exist, is created as a symlink to
-`/nix/var/nix/profiles/per-user/default` if Nix is invoked by the
+`/nix/var/nix/profiles/default` if Nix is invoked by the
 `root` user, or `/nix/var/nix/profiles/per-user/`*username* otherwise.
 
 You can specify another profile location using `--profile` *path*.