anchor.diff: -{ buildPythonPackage
  -, fetchgit
  +{ stdenv
  +, buildPythonPackage
  +, fetchFromGitHub
   , isPy27
   , unittest2
   , cornice
  
positive.code:     cornice gunicorn pyramid requests simplejson sqlalchemy mozsvc tokenserver
      serversyncstorage configparser
    ];
  }
  
negative.code: 
  buildPythonPackage rec {
    pname = "syncserver";
    version = "1.8.0";
    disabled = ! isPy27;
  
    src = fetchFromGitHub {
      owner = "mozilla-services";
      repo = "syncserver";
      rev = version;
      sha256 = "0hxjns9hz7a8r87iqr1yfvny4vwj1rlhwcf8bh7j6lsf92mkmgy8";
    };
  
    buildInputs = [ unittest2 ];
  