{ pkgs }: {
  packageOverrides = super: let
    self = super.pkgs;
  in with self; rec {
    myEmacs = super.callPackage ./emacs.nix {
      emacs = if stdenv.isDarwin then emacs25Macport else emacs;
    };
    nodejs = pkgs.nodejs-8_x;
  };

  allowUnfree = true;
}