anchor.diff:  { stdenv
   , buildPythonPackage
  +, pythonOlder
   , fetchFromGitHub
   , nose
   , noise
  
positive.code:       --replace 'PyPlatec==1.4.0' 'PyPlatec' \
    '';
  
    doCheck = true;
  
    postCheck = ''
      nosetests tests
    '';
  
  
negative.code:     ln -s ${src-data} worldengine-data
    '';
  
    propagatedBuildInputs = [ noise numpy pyplatec protobuf purepng h5py gdal ];
  
    prePatch = ''
  