# nix why-depends

> Show why a package depends on another package.
> More information: <https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-why-depends.html>.

- Show why the currently running NixOS system requires a certain store path:

`nix why-depends {{/run/current-system}} /nix/store/{{checksum-package-version.ext}}`

- Show why a package from nixpkgs requires another package as a _build-time_ dependency:

`nix why-depends --derivation {{nixpkgs#dependent}} {{nixpkgs#dependency}}`
