let
  pkgs = import <nixpkgs> {};
  overlay = pkgs.fetchFromGitHub {
    owner = "mozilla";
    repo = "nixpkgs-mozilla";
    rev = "efda5b357451dbb0431f983cca679ae3cd9b9829";
    sha256 = "11wqrg86g3qva67vnk81ynvqyfj0zxk83cbrf0p9hsvxiwxs8469";
  };
in
  import overlay