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
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);
@ -2107,8 +2107,8 @@ void LocalDerivationGoal::runChild()
bool allowLocalNetworking = parsedDrv->getBoolAttr("__darwinAllowLocalNetworking");
/* 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. */
Path globalTmpDir = canonPath(getEnvNonEmpty("TMPDIR").value_or("/tmp"), true);
to find temporary directories, so we want to open up a broader place for them to put their files, if needed. */
Path globalTmpDir = canonPath(defaultTempDir(), true);
/* They don't like trailing slashes on subpath directives */
if (globalTmpDir.back() == '/') globalTmpDir.pop_back();

View file

@ -429,7 +429,7 @@ void initLibStore() {
/* 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
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");
#endif

View file

@ -582,6 +582,8 @@ public:
Setting<std::string> sandboxShmSize{
this, "50%", "sandbox-dev-shm-size",
R"(
*Linux only*
This option determines the maximum size of the `tmpfs` filesystem
mounted on `/dev/shm` in Linux sandboxes. For the format, see the
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",
"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
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",
"Which prefixes to allow derivations to ask for access to (primarily for Darwin)."};

View file

@ -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,
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)
return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
else
@ -554,7 +558,7 @@ Path createTempDir(const Path & tmpRoot, 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...
// FIXME: use O_TMPFILE.
AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));

View file

@ -258,6 +258,11 @@ Path createTempDir(const Path & tmpRoot = "", 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.
*/

View file

@ -414,8 +414,7 @@ static void main_nix_build(int argc, char * * argv)
// Set the environment.
auto env = getEnv();
auto tmp = getEnv("TMPDIR");
if (!tmp) tmp = getEnv("XDG_RUNTIME_DIR").value_or("/tmp");
auto tmp = defaultTempDir();
if (pure) {
decltype(env) newEnv;
@ -427,7 +426,7 @@ static void main_nix_build(int argc, char * * argv)
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_BUILD_CORES"] = std::to_string(settings.buildCores);

View file

@ -34,6 +34,21 @@ nix-build check.nix -A failed --argstr checkBuildId $checkBuildId \
[ "$status" = "100" ]
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 \
--no-out-link 2> $TEST_ROOT/log
checkBuildTempDirRemoved $TEST_ROOT/log

View file

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