builtins.fetchTarball {url="https://github.com/NixOS/nixpkgs-channels/archive/eee784a1bb6b3e23491e2ee99814d7cb8700db5e.tar.gz"; sha256="1kf4vf2ls743mgqmligr2s9iwidn1y11cpz9pkip6g90fssmjds6";}