import (fetchTarball {
  url = "https://github.com/NixOS/nixpkgs/archive/5c7a370a208d93d458193fc05ed84ced0ba7f387.tar.gz";
  sha256 = "1jkn71xscsk4rb0agbp5saf06hy36qvy512zzh3881pkkn67i9js";
})