kache improves Rust build cache across git worktrees on APFS

The author shares how switching from shared build directories to kache significantly improved Rust build times and disk usage across multiple git worktrees. By storing compiler outputs once and restoring them as copy-on-write APFS clones, kache reduced build times to 14 seconds per worktree while avoiding stale build bugs. Removing an inadvertent coverage instrumentation flag was necessary to allow dependency caching to work properly. Open article →