Since 2.32, nix now needs boost 1.87 or later to build,
due to using unordered::concurrent_flat_map try_emplace_and_cvisit
../src/libexpr/eval.cc: In member function ‘void nix::EvalState::evalFile(const nix::SourcePath&, nix::Value&, bool)’:
../src/libexpr/eval.cc:1096:20: error: ‘class boost::unordered::concurrent_flat_map<nix::SourcePath, nix::Value*, std::hash<nix::SourcePath>, std::equal_to<nix::SourcePath>, traceable_allocator<std::pair<const nix::SourcePath, nix::Value*> > >’ has no member named ‘try_emplace_and_cvisit’; did you mean ‘try_emplace_or_cvisit’?
1096 | fileEvalCache->try_emplace_and_cvisit(
| ^~~~~~~~~~~~~~~~~~~~~~
| try_emplace_or_cvisit
See 834580b539
Previously, `prefetchFile()` used `baseNameOf()` directly on the URL string
to extract the filename. This caused issues with URLs containing query
parameters that include slashes, such as S3 URLs with custom endpoints:
```
s3://bucket/file.txt?endpoint=http://server:9000
```
The `baseNameOf()` function naively searches for the rightmost `/` in the
entire string, which would find the `/` in `http://server:9000` and extract
`server:9000®ion=...` as the filename. This resulted in invalid store
path names containing illegal characters like `:`.
This commit fixes the issue by:
1. Adding a `VerbatimURL::lastPathSegment()` method that extracts the last
non-empty path segment from a URL, using `pathSegments(true)` to filter
empty segments
2. Changing `prefetchFile()` to accept `const VerbatimURL &` and use the new
`lastPathSegment()` method instead of manual path parsing
3. Adding early validation with `checkName()` to fail quickly on invalid
filenames
4. Maintains backward compatibility by falling back to `baseNameOf()` for
unparsable `VerbatimURL`s
I realized that we can actually do this thing, even though it is not
what nlohmann expects at all, because the extra parameter has a default
argument so nlohmann doesn't need to care. Sneaky!
Wrap fmt() calls in lambdas to defer string formatting until the
feature check fails. This avoids unnecessary string formatting in
the common case where the feature is enabled.
Addresses performance concern raised by xokdvium in PR review.
This, alongside the other invariants of the CanonPath is important
to uphold. std::filesystem happily crashes on NUL bytes in the constructor,
as we've seen with `path:%00` prior to c436b7a32a.
Best to stay clear of NUL bytes when we're talking about syscalls, especially
on Unix where strings are null terminated.
Very nice to have if we decide to switch over to pascal-style strings.
Store the reason string as a field in the exception class rather than
only embedding it in the error message. This supports better structured
error handling and future JSON error reporting.
Suggested by Ericson2314 in PR review.
CURL is not very strict about validation of URLs passed to it. We
should reflect this in our handling of URLs that we get from the user
in <nix/fetchurl.nix> or builtins.fetchurl. ValidURL was an attempt to
rectify this, but it turned out to be too strict. The only good way to
resolve this is to pass (in some cases) the user-provided string verbatim
to CURL. Other usages in libfetchers still benefit from using structured
ParsedURL and validation though.
nix store prefetch-file --name foo 'https://cdn.skypack.dev/big.js@^5.2.2'
error: 'https://cdn.skypack.dev/big.js@^5.2.2' is not a valid URL: leftover
Firstly, this is now available on darwin where the default in llvm 19.
Secondly, this leads to very weird segfaults when building with newer nixpkgs for some reason.
(It's UB after all).
This appears when building with the following:
mesonComponentOverrides = finalAttrs: prevAttrs: {
mesonBuildType = "debugoptimized";
dontStrip = true;
doCheck = false;
separateDebugInfo = false;
preConfigure = (prevAttrs.preConfigure or "") + ''
case "$mesonBuildType" in
release|minsize|debugoptimized) appendToVar mesonFlags "-Db_lto=true" ;;
*) appendToVar mesonFlags "-Db_lto=false" ;;
esac
'';
};
And with the following nixpkgs input:
nix build ".#nix-cli" -L --override-input nixpkgs "https://releases.nixos.org/nixos/unstable/nixos-25.11pre870157.7df7ff7d8e00/nixexprs.tar.xz"
Stacktrace:
#0 0x00000000006afdc0 in ?? ()
#1 0x00007ffff71cebb6 in _Unwind_ForcedUnwind_Phase2 () from /nix/store/41ym1jm1b7j3rhglk82gwg9jml26z1km-gcc-14.3.0-lib/lib/libgcc_s.so.1
#2 0x00007ffff71cf5b5 in _Unwind_Resume () from /nix/store/41ym1jm1b7j3rhglk82gwg9jml26z1km-gcc-14.3.0-lib/lib/libgcc_s.so.1
#3 0x00007ffff7eac7d8 in std::basic_ios<char, std::char_traits<char> >::~basic_ios (this=<optimized out>, this=<optimized out>)
at /nix/store/82kmz7r96navanrc2fgckh2bamiqrgsw-gcc-14.3.0/include/c++/14.3.0/bits/basic_ios.h:286
#4 std::__cxx11::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >::basic_ostringstream (this=<optimized out>, this=<optimized out>)
at /nix/store/82kmz7r96navanrc2fgckh2bamiqrgsw-gcc-14.3.0/include/c++/14.3.0/sstream:806
#5 nix::SimpleLogger::logEI (this=<optimized out>, ei=...) at ../logging.cc:121
#6 0x00007ffff7515794 in nix::Logger::logEI (this=0x675450, lvl=nix::lvlError, ei=...) at /nix/store/bkshji3nnxmrmgwa4n2kaxadajkwvn65-nix-util-2.32.0pre-dev/include/nix/util/logging.hh:144
#7 nix::handleExceptions (programName=..., fun=...) at ../shared.cc:336
#8 0x000000000047b76b in main (argc=<optimized out>, argv=<optimized out>) at /nix/store/82kmz7r96navanrc2fgckh2bamiqrgsw-gcc-14.3.0/include/c++/14.3.0/bits/new_allocator.h:88
These are helper programs that execute derivations for specified
system types (e.g. using QEMU to emulate another system type).
To use, set `external-builders`:
external-builders = [{"systems": ["aarch64-linux"], "program": "/path/to/external-builder.py"}]
The external builder gets one command line argument, the path to a JSON file containing all necessary information about the derivation:
{
"args": [...],
"builder": "/nix/store/kwcyvgdg98n98hqapaz8sw92pc2s78x6-bash-5.2p37/bin/bash",
"env": {
"HOME": "/homeless-shelter",
...
},
"realStoreDir": "/tmp/nix/nix/store",
"storeDir": "/nix/store",
"tmpDir": "/tmp/nix-shell.dzQ2hE/nix-build-patchelf-0.14.3.drv-46/build",
"tmpDirInSandbox": "/build"
}
Co-authored-by: Cole Helbling <cole.helbling@determinate.systems>
This is my SNAFU. Accidentally broken in 02c9ac445f.
There's very dubious behavior for 'builtins.readDir /.':
{
outputs =
{ ... }:
{
lib.a = builtins.readDir /.;
};
}
nix eval /tmp/test-flake#lib.a
Starting from 2.27 this now returns an empty set. This really isn't supposed
to happen, but this change in the semantics of makeEmptySourceAccessor accidentally
changed the behavior of this.
Replace non-thread-safe ptsname() calls with a new getPtsName() helper
function that:
- Uses thread-safe ptsname_r() on Linux/BSD platforms
- Uses mutex-protected ptsname() on macOS (which lacks ptsname_r())
This returns the fingerprint for a specific subpath. This is intended
for "composite" accessors like MountedSourceAccessor, where different
subdirectories can have different fingerprints.
Enables builds with ASAN to catch memory corruption
bugs faster and in CI. This is an incredibly valuable
instrument that must be used as much as possible.
Somewhat based on jade's work from Lix, though there's a lot that
we have to do differently:
19ae87e5ce
Co-authored-by: Jade Lovelace <lix@jade.fyi>
