nix3-why-depends
Show why a package depends on another package.
TLDR
Show why the currently running NixOS system requires a certain store path
$ nix why-depends [/run/current-system] [/nix/store/...]
Show why a package from nixpkgs requires another package as a _build-time_ dependency
$ nix why-depends --derivation [nixpkgs#dependent] [nixpkgs#dependency]
