anchor.diff:  
     vega_datasets = callPackage ../development/python-modules/vega_datasets { };
   
  -  virtkey = callPackage ../development/python-modules/virtkey { };
  +  virtkey = callPackage ../development/python-modules/virtkey {
  +    inherit (pkgs) pkgconfig;
  +  };
   
     virtual-display = callPackage ../development/python-modules/virtual-display { };
   
  
positive.code:   poppler-qt5 = callPackage ../development/python-modules/poppler-qt5 {
      inherit (pkgs.qt5) qtbase;
      inherit (pkgs.libsForQt5) poppler;
    };
  
    poyo = callPackage ../development/python-modules/poyo { };
  
negative.code: 
    python-oauth2 = callPackage ../development/python-modules/python-oauth2 { };
  
    python_openzwave = callPackage ../development/python-modules/python_openzwave {
      inherit (pkgs) pkgconfig;
    };
  
    python-Levenshtein = callPackage ../development/python-modules/python-levenshtein { };
  
  