anchor.diff:        sha256 = "06856q6x675ly542ig0plbqcyab6ksfzijlyf1hzhgg3sgwgrcyb";
       };
   
  -    meta = with stdenv.lib; {
  +    meta = {
         description = "helpers to pass trusted data to untrusted environments and back";
         homepage = "https://pypi.python.org/pypi/itsdangerous/";
       };
  
positive.code: 
      doCheck = false; # won't suceed for unknown reasons that look harmless, though
  
      meta = with stdenv.lib; {
        description = "Geometric objects, predicates, and operations";
        homepage = "https://pypi.python.org/pypi/Shapely/";
      };
  
negative.code: 
      propagatedBuildInputs = with self; [ natsort pies ];
  
      meta = {
        description = "A Python utility / library to sort Python imports";
        homepage = https://github.com/timothycrosley/isort;
        license = licenses.mit;
  