[antoniosarosi]

Summary

• normalize bytecode-cache key, manifest, and compilation-unit source paths to portable / separators
• keep cache rel-path generation consistent between CacheContext::open, manifest collection, compiler output, and LSP consumers
• add cross-platform path regressions plus a real on-disk partial-reuse scenario

Root cause

Cache keys, manifest entries, and compiled-unit source_file values were rendered with platform-native separators. That made the serialized cache identity platform-dependent and could make key, manifest, or unit lookups disagree at cache boundaries on Windows.

The macOS temp-root canonicalization half was already fixed on canary by commit 2660b8b9f, which anchors the cache test roots under a canonical temp base; the four partial-reuse tests were already ungated on this baseline. Real on-disk macOS projects were not affected by that test-harness symlink mismatch because project discovery canonicalizes existing roots and source paths, and the new real-project-style regression confirms plan_reuse returns Some with two clean files and one dirty file.

Validation

• BAML_CACHE_DEBUG=1 cargo test -p baml_cli plan_reuse -- --nocapture (17 passed)
• cargo test -p bex_cache relative_paths_use_forward_slashes -- --nocapture
• cargo test -p baml_compiler2_emit relative_source_paths_use_forward_slashes -- --nocapture
• cargo clippy -p bex_cache -p baml_compiler2_emit -p baml_cli --tests -- -D warnings
• cargo fmt --all -- --check

Fixes B-748

Summary by CodeRabbit

• Bug Fixes
  • Improved cache reliability across platforms by standardizing stored file paths.
  • Fixed cache reuse behavior for projects with nested files, allowing unchanged files to remain reusable after edits.
  • Normalized displayed source paths to consistently use forward slashes on Windows and other platforms.

[linear]

B-748

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
beps	Ready	Preview, Comment	Jul 26, 2026 2:09pm
promptfiddle	Ready	Preview, Comment	Jul 26, 2026 2:09pm
promptfiddle2	Ready	Preview, Comment	Jul 26, 2026 2:09pm

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ca741a50-29ac-42e5-a73b-cefb6eb5e9ab

📥 Commits

Reviewing files that changed from the base of the PR and between 788d5c0 and 4397863.

📒 Files selected for processing (3)

• baml_language/crates/baml_cli/src/bytecode_cache.rs
• baml_language/crates/baml_compiler2_emit/src/lib.rs
• baml_language/crates/bex_cache/src/lib.rs

---

📝 Walkthrough

Walkthrough

Cache key inputs, manifest paths, and compiler source paths now use portable root-relative paths with / separators. Tests cover normalized paths, expected cache keys, manifest entries, and partial reuse after editing a nested source file.

Changes

Portable path normalization

Layer / File(s)	Summary
Normalize cache path contracts baml_language/crates/bex_cache/src/lib.rs	rel_path now emits /-separated root-relative paths, with updated key and manifest documentation and unit coverage.
Normalize compiler source paths baml_language/crates/baml_compiler2_emit/src/lib.rs	relative_source_path normalizes nested project paths to forward slashes and verifies the result with a unit test.
Apply portable paths to cache reuse baml_language/crates/baml_cli/src/bytecode_cache.rs	Cache key generation uses rel_path; integration coverage verifies portable manifest entries and partial reuse after one file changes.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• BoundaryML/baml#3924: Introduced the content-addressed caching code whose path inputs are normalized here.

Suggested reviewers: hellovai

Poem

I’m a bunny with paths in my paws,
Making slashes agree with the laws.
Keys stay neat, manifests align,
Nested files reuse just fine.
Hop, hop—portable by design!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: normalizing bytecode-cache relative paths across platforms.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch antoniosarosi/b-748

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

⏭️ Performance benchmarks were skipped

Perf benchmarks (CodSpeed) are opt-in on pull requests — they no longer run on every push. They always run automatically after merge to canary/main.

To run them on this PR, do any of the following, then push a commit (or re-run CI):

• Add RUN_CODSPEED=1 to the PR description, or
• Include run-perf or /perf in the PR title or any commit message.

[github-actions]

Binary size checks passed

✅ 7 passed

	Artifact	Platform	File	Gzip	Gated on	Baseline	Delta	Status
✅	baml-cli	Linux	🔒 27.2 MB	11.6 MB	file	27.1 MB	+150.9 KB (+0.6%)	OK
✅	packed-program	Linux	🔒 17.6 MB	7.3 MB	file	17.6 MB	+7.2 KB (+0.0%)	OK
✅	baml-cli	macOS	🔒 21.2 MB	10.1 MB	file	21.0 MB	+149.1 KB (+0.7%)	OK
✅	packed-program	macOS	🔒 13.8 MB	6.4 MB	file	13.8 MB	+33.1 KB (+0.2%)	OK
✅	baml-cli	Windows	🔒 22.8 MB	10.3 MB	file	22.7 MB	+126.0 KB (+0.6%)	OK
✅	packed-program	Windows	🔒 14.7 MB	6.5 MB	file	14.7 MB	+4.6 KB (+0.0%)	OK
✅	bridge_wasm	WASM	16.5 MB	🔒 4.5 MB	gzip	4.5 MB	+18.6 KB (+0.4%)	OK

🔒 = the size this artifact is GATED on (ceiling + delta). Binaries gate on file size (installed binary); WASM gates on gzip (download size). The other size is shown for information only.

---

Generated by cargo size-gate · workflow run

[antoniosarosi]

Closing — this was an orchestration experiment run; not landing.