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DRMacIver
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- TempRustProject: use PID-based temp target dirs to prevent parallel
test binaries from racing on shared build cache
- test_output: accept both {closure#0} and {{closure}} backtrace formats
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Liam-DeVoe
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| // cache build output from TempRustProject across tests. Compilation time is substantial | ||
| // (10+ seconds) and this lets us only incur that cost on the first test. | ||
| // Cache build output from TempRustProject across tests within the same process. | ||
| // | ||
| // We clear the dir at the start to ensure a fresh environment on each test run. | ||
| // Under coverage (CARGO_LLVM_COV=1), we reuse the main project's llvm-cov target | ||
| // dir so that subprocess builds share the same instrumented artifacts. This lets | ||
| // cargo-llvm-cov's report phase map subprocess profraw data back to source files. | ||
| // Cargo's internal file locks prevent corruption from concurrent access. | ||
| // | ||
| // Outside coverage, each test binary gets its own target dir (via PID) to avoid | ||
| // heavy lock contention when multiple test binaries build in parallel. | ||
| static SHARED_TARGET_DIR: LazyLock<PathBuf> = LazyLock::new(|| { | ||
| let path = std::env::temp_dir().join("hegel-test-cargo-target"); | ||
| if std::env::var("CARGO_LLVM_COV").is_ok() { | ||
| let path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("target/llvm-cov-target"); | ||
| return path; | ||
| } | ||
| let path = std::env::temp_dir().join(format!("hegel-test-cargo-target-{}", std::process::id())); | ||
| let _ = std::fs::remove_dir_all(&path); |
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Why have we changed from a shared target dir to mixing in pid outside of coverage? This lessens the benefit of a shared target dir for compilation times by a factor of n where n is the number of cores
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Fix two flaky/broken tests:
TempRustProject: PID-based temp target dirs to prevent parallel test binary racestest_output: accept both{closure#0}and{{closure}}backtrace formats (Rust 1.92 changed the stable format)