anchor.diff:    src = fetchurl {
       name = "${name}.tar.gz";
       url = "https://cgit.freedesktop.org/xdg/xdg-utils/snapshot/${rev}.tar.gz";
  -    multihash = "QmTYcdd5NwEfG4cS9aGLKjYsjmYiVnYVpSQPRQtUnqVuuA";
  -    sha256 = "541ba6e0b8c090f387ed6858d7da202dbbcf5d7701d257d76ebaeea538bef3b7";
  +    multihash = "QmWgBkZtmwisnmDut85mWXP6MutN34i6VHJgWtj1V2wbvC";
  +    sha256 = "7933aaea46227c70adcaab75d9360caa251f4589be6e56268eeee157c22fb089";
     };
   
     buildInputs = [
  
positive.code: }:
  
  let
    rev = "338f54e0dbf3d9e9583f34c9dde194c39ba0b4e8";
    version = "2016-06-10";
  in
  stdenv.mkDerivation rec {
    name = "xdg-utils-${version}";
  
negative.code:     done
    '';
  
    meta = with lib; {
      description = "Desktop integration utilities";
      homepage = http://portland.freedesktop.org/wiki/;
      license = licenses.mit;
  