anchor.diff:  { lib
  +, apptools
  +, buildPythonPackage
   , fetchPypi
  -, isPy27
  -, buildPythonPackage
  +, ipython
  +, pytestCheckHook
  +, pythonAtLeast
  +, pythonOlder
  +, setuptools
   , traits
  -, apptools
  -, pytestCheckHook
  -, ipython
  -, setuptools
   }:
   
   buildPythonPackage rec {
     pname = "envisage";
     version = "6.0.1";
  +  format = "setuptools";
   
  -  disabled = isPy27;
  +  disabled = pythonOlder "3.6";
   
     src = fetchPypi {
       inherit pname version;
  
positive.code: 
    # for the optional dependency ipykernel, only versions < 6 are
    # supported, so it's not included in the tests, and not propagated
    propagatedBuildInputs = [ traits apptools setuptools ];
  
    preCheck = ''
      export HOME=$PWD/HOME
  
negative.code:     pytestCheckHook
    ];
  
    disabledTestPaths = lib.optionals (pythonAtLeast "3.10") [
      # https://github.com/enthought/envisage/issues/455
      "envisage/tests/test_egg_basket_plugin_manager.py"
      "envisage/tests/test_egg_plugin_manager.py"
    ];
  
    pythonImportsCheck = [
      "envisage"
    ];
  
    meta = with lib; {
      description = "Framework for building applications whose functionalities can be extended by adding plug-ins";
      homepage = "https://github.com/enthought/envisage";
      license = licenses.bsdOriginal;
      maintainers = with lib.maintainers; [ knedlsepp ];
    };
  }
  