anchor.diff:  buildPythonPackage rec {
     pname = "pyxnat";
     version = "1.4";
  -  disabled = isPy27;
  +  disabled = pythonOlder "3.7";
   
     src = fetchPypi {
       inherit pname version;
  
positive.code: { lib
  , buildPythonPackage
  , fetchPypi
  , isPy27
  , nose
  , lxml
  , requests
  
negative.code:   };
  
    propagatedBuildInputs = [ lxml requests ];
  
    # future is not used, and pathlib is installed part of python38+
    # w/o an external package
    prePatch = ''
      substituteInPlace setup.py \
        --replace "pathlib>=1.0" "" \
        --replace "future>=0.16" ""
    '';
  
    checkInputs = [ nose ];
    checkPhase = "nosetests pyxnat/tests";
  