import (builtins.fetchTarball {
  url = "https://github.com/NixOS/nixpkgs/archive/4263ba5e133cc3fc699c1152ab5ee46ef668e675.tar.gz";
  sha256 = "1nzqrdw0lhbldbs9r651zmgqpwhjhh9sssykhcl2155kgsfsrk7i";
}) {}