Add build-dir setting, clean up default TMPDIR handling

This is a squash of upstream PRs #10303, #10312 and #10883.

fix: Treat empty TMPDIR as unset

Fixes an instance of

    nix: src/libutil/util.cc:139: nix::Path nix::canonPath(PathView, bool): Assertion `path != ""' failed.

... which I've been getting in one of my shells for some reason.
I have yet to find out why TMPDIR was empty, but it's no reason for
Nix to break.

(cherry picked from commit c3fb2aa1f9d1fa756dac38d3588c836c5a5395dc)

fix: Treat empty XDG_RUNTIME_DIR as unset

See preceding commit. Not observed in the wild, but is sensible
and consistent with TMPDIR behavior.

(cherry picked from commit b9e7f5aa2df3f0e223f5c44b8089cbf9b81be691)

local-derivation-goal.cc: Reuse defaultTempDir()

(cherry picked from commit fd31945742710984de22805ee8d97fbd83c3f8eb)

fix: remove usage of XDG_RUNTIME_DIR for TMP

(cherry picked from commit 1363f51bcb24ab9948b7b5093490a009947f7453)

tests/functional: Add count()

(cherry picked from commit 6221770c9de4d28137206bdcd1a67eea12e1e499)

Remove uncalled for message

(cherry picked from commit b1fe388d33530f0157dcf9f461348b61eda13228)

Add build-dir setting

(cherry picked from commit 8b16cced18925aa612049d08d5e78eccbf0530e4)
Change-Id: Ic7b75ff0b6a3b19e50a4ac8ff2d70f15c683c16a
This commit is contained in:
Robert Hensing 2024-03-22 22:41:50 +01:00 committed by K900
parent 4c3d93611f
commit d86009bd76
9 changed files with 74 additions and 14 deletions

View file

@ -0,0 +1,12 @@
---
synopsis: "Add a `build-dir` setting to set the backing directory for builds"
cls: 1514
credits: [roberth, tomberek]
category: Improvements
---
`build-dir` can now be set in the Nix configuration to choose the backing directory for the build sandbox.
This can be useful on systems with `/tmp` on tmpfs, or simply to relocate large builds to another disk.
Also, `XDG_RUNTIME_DIR` is no longer considered when selecting the default temporary directory,
as it's not intended to be used for large amounts of data.

View file

@ -495,7 +495,7 @@ void LocalDerivationGoal::startBuilder()
/* Create a temporary directory where the build will take /* Create a temporary directory where the build will take
place. */ place. */
tmpDir = createTempDir("", "nix-build-" + std::string(drvPath.name()), false, false, 0700); tmpDir = createTempDir(settings.buildDir.get().value_or(""), "nix-build-" + std::string(drvPath.name()), false, false, 0700);
chownToBuilder(tmpDir); chownToBuilder(tmpDir);
@ -2107,8 +2107,8 @@ void LocalDerivationGoal::runChild()
bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking"); bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking");
/* The tmpDir in scope points at the temporary build directory for our derivation. Some packages try different mechanisms /* The tmpDir in scope points at the temporary build directory for our derivation. Some packages try different mechanisms
to find temporary directories, so we want to open up a broader place for them to dump their files, if needed. */ to find temporary directories, so we want to open up a broader place for them to put their files, if needed. */
Path globalTmpDir = canonPath(getEnvNonEmpty("TMPDIR").value_or("/tmp"), true); Path globalTmpDir = canonPath(defaultTempDir(), true);
/* They don't like trailing slashes on subpath directives */ /* They don't like trailing slashes on subpath directives */
if (globalTmpDir.back() == '/') globalTmpDir.pop_back(); if (globalTmpDir.back() == '/') globalTmpDir.pop_back();

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@ -429,7 +429,7 @@ void initLibStore() {
/* On macOS, don't use the per-session TMPDIR (as set e.g. by /* On macOS, don't use the per-session TMPDIR (as set e.g. by
sshd). This breaks build users because they don't have access sshd). This breaks build users because they don't have access
to the TMPDIR, in particular in nix-store --serve. */ to the TMPDIR, in particular in nix-store --serve. */
if (getEnv("TMPDIR").value_or("/tmp").starts_with("/var/folders/")) if (defaultTempDir().starts_with("/var/folders/"))
unsetenv("TMPDIR"); unsetenv("TMPDIR");
#endif #endif

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@ -582,6 +582,8 @@ public:
Setting<std::string> sandboxShmSize{ Setting<std::string> sandboxShmSize{
this, "50%", "sandbox-dev-shm-size", this, "50%", "sandbox-dev-shm-size",
R"( R"(
*Linux only*
This option determines the maximum size of the `tmpfs` filesystem This option determines the maximum size of the `tmpfs` filesystem
mounted on `/dev/shm` in Linux sandboxes. For the format, see the mounted on `/dev/shm` in Linux sandboxes. For the format, see the
description of the `size` option of `tmpfs` in mount(8). The default description of the `size` option of `tmpfs` in mount(8). The default
@ -589,9 +591,27 @@ public:
)"}; )"};
Setting<Path> sandboxBuildDir{this, "/build", "sandbox-build-dir", Setting<Path> sandboxBuildDir{this, "/build", "sandbox-build-dir",
"The build directory inside the sandbox."}; R"(
*Linux only*
The build directory inside the sandbox.
This directory is backed by [`build-dir`](#conf-build-dir) on the host.
)"};
#endif #endif
Setting<std::optional<Path>> buildDir{this, std::nullopt, "build-dir",
R"(
The directory on the host, in which derivations' temporary build directories are created.
If not set, Nix will use the system temporary directory indicated by the `TMPDIR` environment variable.
Note that builds are often performed by the Nix daemon, so its `TMPDIR` is used, and not that of the Nix command line interface.
This is also the location where [`--keep-failed`](@docroot@/command-ref/opt-common.md#opt-keep-failed) leaves its files.
If Nix runs without sandbox, or if the platform does not support sandboxing with bind mounts (e.g. macOS), then the [`builder`](@docroot@/language/derivations.md#attr-builder)'s environment will contain this directory, instead of the virtual location [`sandbox-build-dir`](#conf-sandbox-build-dir).
)"};
Setting<PathSet> allowedImpureHostPrefixes{this, {}, "allowed-impure-host-deps", Setting<PathSet> allowedImpureHostPrefixes{this, {}, "allowed-impure-host-deps",
"Which prefixes to allow derivations to ask for access to (primarily for Darwin)."}; "Which prefixes to allow derivations to ask for access to (primarily for Darwin)."};

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@ -511,10 +511,14 @@ void AutoDelete::reset(const Path & p, bool recursive) {
////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////
std::string defaultTempDir() {
return getEnvNonEmpty("TMPDIR").value_or("/tmp");
}
static Path tempName(Path tmpRoot, const Path & prefix, bool includePid, static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
std::atomic<unsigned int> & counter) std::atomic<unsigned int> & counter)
{ {
tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); tmpRoot = canonPath(tmpRoot.empty() ? defaultTempDir() : tmpRoot, true);
if (includePid) if (includePid)
return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++); return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
else else
@ -554,7 +558,7 @@ Path createTempDir(const Path & tmpRoot, const Path & prefix,
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix) std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
{ {
Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX"); Path tmpl(defaultTempDir() + "/" + prefix + ".XXXXXX");
// Strictly speaking, this is UB, but who cares... // Strictly speaking, this is UB, but who cares...
// FIXME: use O_TMPFILE. // FIXME: use O_TMPFILE.
AutoCloseFD fd(mkstemp((char *) tmpl.c_str())); AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));

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@ -258,6 +258,11 @@ Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
*/ */
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix"); std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
/**
* Return `TMPDIR`, or the default temporary directory if unset or empty.
*/
Path defaultTempDir();
/** /**
* Used in various places. * Used in various places.
*/ */

View file

@ -414,8 +414,7 @@ static void main_nix_build(int argc, char * * argv)
// Set the environment. // Set the environment.
auto env = getEnv(); auto env = getEnv();
auto tmp = getEnv("TMPDIR"); auto tmp = defaultTempDir();
if (!tmp) tmp = getEnv("XDG_RUNTIME_DIR").value_or("/tmp");
if (pure) { if (pure) {
decltype(env) newEnv; decltype(env) newEnv;
@ -427,7 +426,7 @@ static void main_nix_build(int argc, char * * argv)
env["__ETC_PROFILE_SOURCED"] = "1"; env["__ETC_PROFILE_SOURCED"] = "1";
} }
env["NIX_BUILD_TOP"] = env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = *tmp; env["NIX_BUILD_TOP"] = env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmp;
env["NIX_STORE"] = store->storeDir; env["NIX_STORE"] = store->storeDir;
env["NIX_BUILD_CORES"] = std::to_string(settings.buildCores); env["NIX_BUILD_CORES"] = std::to_string(settings.buildCores);

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@ -34,6 +34,21 @@ nix-build check.nix -A failed --argstr checkBuildId $checkBuildId \
[ "$status" = "100" ] [ "$status" = "100" ]
if checkBuildTempDirRemoved $TEST_ROOT/log; then false; fi if checkBuildTempDirRemoved $TEST_ROOT/log; then false; fi
test_custom_build_dir() {
local customBuildDir="$TEST_ROOT/custom-build-dir"
# Nix does not create the parent directories, and perhaps it shouldn't try to
# decide the permissions of build-dir.
mkdir "$customBuildDir"
nix-build check.nix -A failed --argstr checkBuildId $checkBuildId \
--no-out-link --keep-failed --option build-dir "$TEST_ROOT/custom-build-dir" 2> $TEST_ROOT/log || status=$?
[ "$status" = "100" ]
[[ 1 == "$(count "$customBuildDir/nix-build-"*)" ]]
local buildDir="$customBuildDir/nix-build-"*
grep $checkBuildId $buildDir/checkBuildId
}
test_custom_build_dir
nix-build check.nix -A deterministic --argstr checkBuildId $checkBuildId \ nix-build check.nix -A deterministic --argstr checkBuildId $checkBuildId \
--no-out-link 2> $TEST_ROOT/log --no-out-link 2> $TEST_ROOT/log
checkBuildTempDirRemoved $TEST_ROOT/log checkBuildTempDirRemoved $TEST_ROOT/log

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@ -274,6 +274,11 @@ grepQuietInverse() {
! grep "$@" > /dev/null ! grep "$@" > /dev/null
} }
# Return the number of arguments
count() {
echo $#
}
trap onError ERR trap onError ERR
fi # COMMON_VARS_AND_FUNCTIONS_SH_SOURCED fi # COMMON_VARS_AND_FUNCTIONS_SH_SOURCED