anchor.diff:  buildPythonPackage rec {
     pname = "transitions";
     version = "0.8.10";
  +  format = "setuptools";
   
     src = fetchPypi {
       inherit pname version;
  
positive.code:     export HOME=$TMPDIR
    '';
  
    meta = with lib; {
      homepage = "https://github.com/pytransitions/transitions";
      description = "A lightweight, object-oriented finite state machine implementation in Python";
  
negative.code: { lib
  , buildPythonPackage
  , fetchPypi
  , pythonAtLeast
  , six
  , pygraphviz
  , pytestCheckHook
  