anchor.diff:      find "$out" -name _spotify.so -exec \
           install_name_tool -change \
           @loader_path/../Frameworks/libspotify.framework/libspotify \
  -        ${pkgs.libspotify}/lib/libspotify.dylib \
  +        ${libspotify}/lib/libspotify.dylib \
           {} \;
     '';
   
  
positive.code: , buildPythonPackage
  , fetchFromGitHub
  , cffi
  , pkgs
  }:
  
  buildPythonPackage rec {
  
negative.code:   };
  
    propagatedBuildInputs = [ cffi ];
    buildInputs = [ libspotify ];
  
    # python zip complains about old timestamps
    preConfigure = ''
  