Finding files in Nix packages:

Nix packages live in /nix/store with unique hashes. Each package can have multiple "outputs" (out/dev/doc/man) - separate store paths for binaries, headers, docs, etc. Get a package's path:

$ nix eval --raw nixpkgs#bash
/nix/store/f43k3lffqlz3n864inxz8zf28jvks1q6-bash-interactive-5.3p3