import (fetchTarball {
  url = "https://github.com/NixOS/nixpkgs/archive/3c0e3697520cbe7d9eb3a64bfd87de840bf4aa77.tar.gz";
  sha256 = "1vx7kyaq0i287dragjgfdj94ggwr3ky2b7bq32l8rkd2k3vc3gl5";
})