fix(luggage): serialize shim-writing idempotency tests to close fork/exec race - #459
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…exec race The four `installer::idempotency` tests that write a shell shim and then `Command::output()` it intermittently failed under parallel `cargo test` due to the well-known fork+ETXTBSY race (rust-lang/rust#100904): one thread's in-flight write FD raises the inode's i_writecount while another thread forks for execve, and the child gets ETXTBSY. Add `serial_test` as a dev-dependency and mark the three shim-writing tests (`matching_version_returns_true`, `nonmatching_version_returns_false`, `rust_tool_id_resolves_to_rustc_binary`) with `#[serial_test::serial]` so their write+exec windows cannot overlap. Verified by running `cargo test -p luggage --lib installer::idempotency` 25x consecutively — all green. Full `cargo test -p luggage` and `cargo clippy -p luggage --tests -- -D warnings` also clean. The two tests that don't write a shim (`missing_binary_returns_false`, `primary_binary_defaults_to_tool_id`) are left parallel — they don't participate in the race. Closes #456 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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…c race (#481) The three `installer::validate` tests that write a shell shim and then `Command::output()` it intermittently fail under parallel `cargo test` due to the same fork+ETXTBSY race (rust-lang/rust#100904) that #459 fixed for `installer::idempotency`: one thread's in-flight write FD raises the inode's i_writecount while another thread forks for execve, and the child gets ETXTBSY. Validate's tests use the identical `write_shim` pattern but were never serialized. Observed in CI run 25982111224 on the merge-to-main of #479, where `mismatched_output_returns_validation_failed` failed with `assertion failed: message.contains("1.95.0")` — the shim's exec returned an ETXTBSY error message that, naturally, doesn't contain the target version string. Ubuntu's faster fork/exec exposes the race more reliably than macOS / Windows. Mark all three shim-writing tests (`matching_output_passes`, `mismatched_output_returns_validation_failed`, `propagates_env_to_subprocess`) with `#[serial_test::serial]`. The crate's `serial_test` dev-dependency was already added in #459. Verified by running `cargo test -p luggage --lib installer::validate` 25x consecutively — all green. Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
serial_test = \"3\"tocrates/luggage[dev-dependencies].crates/luggage/src/installer/idempotency.rs(matching_version_returns_true,nonmatching_version_returns_false,rust_tool_id_resolves_to_rustc_binary) with#[serial_test::serial].cargo testfork/exec race (rust-lang/rust#100904) where an in-flightfs::writeFD raised the inode'si_writecountwhile another threadfork()+execve()'d a shim — child gotETXTBSY. CI run 25649484773 caught one variant onmainpost-feat(containers-common): broaden Zed extensions on dev_tools and docker #453.The two tests that don't write a shim (
missing_binary_returns_false,primary_binary_defaults_to_tool_id) are left parallel — they don't participate in the race. Production code (already_installed,primary_binary) is unchanged.Test plan
cargo test -p luggage --lib installer::idempotency— 25 consecutive iterations, all greencargo test -p luggage— full crate suite green (lib + integration + doc)cargo clippy -p luggage --tests -- -D warnings— cleanRust Tests (stibbons) — ubuntu-latestgreen on this PRmainruns green to confirmCloses #456
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