Cached builds: unchanged sources keep their timestamps issue #52 closed: completed andymccall opened this 22 days ago · 0 comments

Cargo judges freshness by mtime, and a fresh checkout gives every file a new one, so a cached target still rebuilds every path crate (12 in oxygenhub run 226's test, 2 min 31 s). Keep a manifest beside each cached disk (path, BLAKE3, mtime of the sources it was built from); at checkout, a file whose content matches gets the recorded mtime back, a changed file keeps now. Unchanged crates stay fresh; changed ones always rebuild.