anchor.diff:    };
   
     # macOS needs clang for testing
  -  buildInputs = [
  +  checkInputs = [
       pytest hypothesis zope_interface pympler coverage six
     ] ++ lib.optionals (stdenv.isDarwin) [ clang ];
   
  
positive.code: , pympler, coverage, six, clang }:
  
  buildPythonPackage rec {
    name = "${pname}-${version}";
    pname = "attrs";
    version = "17.4.0";
  
  
negative.code:     py.test
    '';
  
    # To prevent infinite recursion with pytest
    doCheck = false;
  
    meta = with lib; {
      description = "Python attributes without boilerplate";
      homepage = https://github.com/hynek/attrs;
  