angrr

Users can define custom retention periods and rules for different GC root types, such as temporary roots from nix-direnv or profile generations, as shown in the detailed configuration examples in the README.

Once configured, angrr runs periodically via the NixOS module or other setups, automatically removing stale roots without manual intervention, ideal for set-and-forget maintenance.

The tool provides a direnv library that automatically touches GC roots when projects are accessed, ensuring active environments are retained, as demonstrated in the integration examples.

The --dry-run option allows previewing deletions without making changes, reducing the risk of accidental data loss during policy testing.