cfdg: 3.3 -> 3.4.1

stdenv.mkDerivation rec {

  pname = "cfdg";

  version = "3.3";

  version = "3.4.1";

  src = fetchFromGitHub {

    owner = "MtnViewJohn";

    repo = "context-free";

    rev = "Version${version}";

    sha256 = "13m8npccacmgxbs4il45zw53dskjh53ngv2nxahwqw8shjrws4mh";

    sha256 = "sha256-f2VMb0TM50afKf/lGdZBP2z13UrCVgG4/IYi5gnD+ow=";

  };

  nativeBuildInputs = [ bison flex ];