v0.6.0

Summary

kache is a content-addressed Rust build cache that plugs in as a RUSTC_WRAPPER.
0.5.0 designed a correct cache key; 0.6.0 makes that key portable across machines and
checkouts and extends caching to the C/C++ that crates compile in build scripts.

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Why

A shared cache only helps if two checkouts of the same source hit the same entry — and
they usually don't, because absolute build paths leak into the key. 0.6.0 closes that gap,
and pulls the C/C++ half of many build times (ring, openssl-sys, Firefox) under the
same cache.

What's new

• Cross-checkout sharing. KACHE_BASE_DIR normalizes the build root; opt-in
  [cache] path_only_env_vars (or KACHE_PATH_ONLY_ENV_VARS) marks build-location env
  vars so they normalize instead of poisoning the key.
• C/C++ via clang-cl (incl. Windows/MSVC). kache now caches MSVC-style cl/clang-cl,
  not just gcc/clang — no extra config if kache is already your wrapper.
• KACHE_LOCAL_ONLY — disable all remote I/O for air-gapped/private builds.
• KACHE_VERIFY_RESTORES — opt-in re-hash of restored blobs before use.

Hardening for shared use: length-prefixed key fields (cache v16), file metadata folded
into the dedup hash, and a cross-process gc.lock.

These notes were drafted with LLM assistance and edited by the maintainers (@jleni, @emmanuelm41).

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Changelog

• bench(firefox): cross-clone cache convergence — 119→2 diverging, 8.45× speedup by @jleni in #258
• deps: drop aws-lc-sys (use ring) — unblocks aarch64-pc-windows-msvc by @jleni in #257
• Use guppy for build intent discovery by @jleni in #262
• Unify e2e and benchmark scenarios by @jleni in #261
• Fix Windows full compiler path detection by @jleni in #264
• Use guppy crate order for prefetch planning by @jleni in #263
• Improve build report diagnostics by @jleni in #265
• chore: bump release to 0.5.1-rc.1 by @jleni in #266
• Separate hit, dup, and miss cache outcomes by @jleni in #267
• Document report cache outcomes by @jleni in #268
• Bound Windows daemon IPC reads by @jleni in #269
• Guard OUT_DIR dual-pattern cache keys by @jleni in #270
• Refuse to cache rustc @argfile invocations (false-hit fix) by @jleni in #282
• Validate untrusted cache_key/crate_name before path/key interpolation by @jleni in #283
• Reclaim orphaned blob files via a GC + doctor sweep by @jleni in #284
• fix(rustc): recognize clippy-driver.exe under cargo clippy on Windows by @emmanuelm41 in #289
• fix(daemon): wake accept loop immediately on stop (#288) by @emmanuelm41 in #291
• Forward cc-crate family probe to the real compiler (fixes #286) by @emmanuelm41 in #290
• chore(release): bump version to 0.5.1-rc.2 by @emmanuelm41 in #292
• chore(release): bump version to 0.5.1-rc.3 by @emmanuelm41 in #294
• Robustness quick wins: list_keys loop, blob dir fsync, RUSTC_BOOTSTRAP key, spawn-failure fallback by @jleni in #293
• chore(release): bump version to 0.5.1-rc.4 by @emmanuelm41 in #296
• fix(cc): pre-clean read-only restored objects before recompiling on a cache miss by @emmanuelm41 in #297
• clang-cl support — Layers 0/1/2/4: dialect tables, /EP probe, cacheable cl + Firefox flags (#285) by @emmanuelm41 in #295
• fix(#298): keep restored Rust --test executables executable + regression coverage by @emmanuelm41 in #302
• fix(cc): splice -ffile-prefix-map flags before the -- separator (#300) by @emmanuelm41 in #305
• test(cc): guard #299 — clang-cl invocations get zero injected flags by @emmanuelm41 in #306
• chore(release): bump version to 0.6.0-rc.1 by @emmanuelm41 in #307
• Daemon + remote robustness hardening (bounded reads, HEAD retry, download guard, GC perf) by @jleni in #308
• monitor: Live Build as a table + surface the build action/outcome by @jleni in #309
• fix(#311): binstall pkg-url derives extension from pkg-fmt — Windows ships .zip by @emmanuelm41 in #313
• feat(cc): cache clang-cl debug compiles (#312) by @emmanuelm41 in #315
• fix(cc): Windows-aware -### path sentinel for gnu/clang (#312 follow-up) by @emmanuelm41 in #316
• docs: audit + correct the docs against the codebase (and fix the monitor dedup metric) by @jleni in #317
• fix(cc): map the Apple SDK path to a sentinel for portable cc keys (#78) by @jleni in #318
• fix(store,remote): harden the remote-import + store-removal seam (#212, #276, #211, #213) by @jleni in #320
• feat(config): strict local-only mode (KACHE_LOCAL_ONLY / [cache] local_only) by @jleni in #321
• fix(daemon): offload Gc/Stats/HashFiles + periodic GC to spawn_blocking (#281) by @jleni in #322
• fix(daemon): hash files outside the store mutex in HashFiles (#281) by @jleni in #338
• fix(store): fold inode into the file-hash memo key (#324) by @jleni in #341
• fix(store): fold name/size/exec-bit into the content-dedup hash (#324) by @jleni in #340
• fix(cache): never cache a degraded dep-info pre-pass (#323) by @jleni in #339
• feat(cache): opt-in too-new-input guard — refuse to store racy compiles (#324) by @jleni in #342
• feat(cache): length-prefix free-text key fields, bump to v16 (#324) by @jleni in #343
• feat(store): opt-in content verification on local restore (#332) by @jleni in #344
• ci: pin mise CLI to dodge v2026.6.10 Windows regression (+ bounded e2e retry) by @jleni in #346
• feat(store): cross-process gc.lock so concurrent GC drivers don't double-scan (#326) by @jleni in #345
• Fix GC lock contention follow-ups by @jleni in #347
• chore(release): bump version to 0.6.0 by @emmanuelm41 in #349

Full Changelog: v0.5.0...v0.6.0