cargo-quota

cargo clean throws everything away. A normal build keeps everything forever. cargo-quota sits in between: when a target directory goes over its budget, it removes artifacts oldest-first until it’s back under, and it never touches anything you’ve used recently.

$ cargo quota build --release
     Pruning /home/me/proj/target is 41.2 GiB, over its 37.3 GiB budget (2% of 1.8 TiB)
     Removed 812 artifacts (11.7 GiB) unused for 19d or longer, leaving 29.5 GiB
   Compiling proj v0.1.0 (/home/me/proj)
    Finished `release` profile [optimized] target(s) in 4.12s

• Budget is a percentage of disk space (5% by default), set per project in Cargo.toml or globally with an environment variable.
• Pruning works on whole compilation units, grouped by the hash cargo puts in every artifact name. Cargo rebuilds a removed unit only if it’s needed again.
• Safety: anything used within the last hour is kept, and a profile directory with a build in progress is skipped by taking cargo’s own lock.
• Worktrees: --worktrees puts every git worktree of a repository under one shared budget, so abandoned worktrees get pruned first.

Cargo has no pre-build hook, so a shell wrapper or cargo aliases route build, test, and friends through cargo quota. The README has both.

cargo install cargo-quota