anchor.diff:  
   let
   
  -  inherit (pythonPackages) buildPythonPackage python isPy3k pyqt5 enum34;
  +  inherit (pythonPackages) buildPythonPackage python isPy3k pyqt5 enum34 pyqt-builder;
     inherit (pyqt5) sip;
     # source: https://www.riverbankcomputing.com/pipermail/pyqt/2020-June/042985.html
     patches = lib.optional (lib.hasPrefix "5.14" pyqt5.version)
  
positive.code:     runHook postConfigure
    '';
  
    postInstall = ''
      # Let's make it a namespace package
      cat << EOF > $out/${python.sitePackages}/PyQt5/__init__.py
      from pkgutil import extend_path
  
negative.code: in buildPythonPackage rec {
    pname = "PyQtWebEngine";
    version = "5.15.4";
    format = if isPy3k then "pyproject" else "other";
  
    src = pythonPackages.fetchPypi {
      inherit pname version;
  