anchor.diff:  
   buildPythonPackage rec {
     pname = "libcst";
  -  version = "0.4.1";
  +  version = "0.4.3";
     format = "pyproject";
   
  -  disabled = pythonOlder "3.6";
  +  disabled = pythonOlder "3.7";
   
     src = fetchFromGitHub {
       owner = "instagram";
       repo = pname;
       rev = "v${version}";
  -    sha256 = "sha256-soAlt1KBpCn5JxM1b2LZ3vOpBn9HPGdbm+BBYbyEkfE=";
  +    sha256 = "sha256-Lm62rVL5f+fu4KzOQMroM0Eu27l5v2dkGtRiIVPFNhg=";
     };
   
     cargoDeps = rustPlatform.fetchCargoTarball {
       inherit src;
       sourceRoot = "source/${cargoRoot}";
       name = "${pname}-${version}";
  -    hash = "sha256:1rz1c0dv3f1h2m5hwdisl3rbqnmifbva4f0c4vygk7rh1q27l515";
  +    hash = "sha256-i5BYYiILadKEPIJOaWdG1lZNSHfNQnwmc5j0D1jg/kc=";
     };
   
     cargoRoot = "native";
  
positive.code:     description = "Concrete Syntax Tree (CST) parser and serializer library for Python";
      homepage = "https://github.com/Instagram/libcst";
      license = with licenses; [ mit asl20 psfl ];
      maintainers = with maintainers; [ ruuda SuperSandro2000 ];
    };
  }
  
negative.code:   buildInputs = lib.optionals stdenv.isDarwin [ libiconv ];
  
    propagatedBuildInputs = [
      typing-extensions
      typing-inspect
      pyyaml
    ];
  
    checkInputs = [
      hypothesis
      pytestCheckHook
    ];
  
  