tdlib: 1.8.19 -> 1.8.21

stdenv.mkDerivation rec {

  pname = "tdlib";

  version = "1.8.19";

  version = "1.8.21";

  src = fetchFromGitHub {

    owner = "tdlib";

    # The tdlib authors do not set tags for minor versions, but

    # external programs depending on tdlib constrain the minor

    # version, hence we set a specific commit with a known version.

    rev = "2589c3fd46925f5d57e4ec79233cd1bd0f5d0c09";

    hash = "sha256-mbhxuJjrV3nC8Ja7N0WWF9ByHovJLmoLLuuzoU4khjU=";

    rev = "3870c29b158b75ca5e48e0eebd6b5c3a7994a000";

    hash = "sha256-MCzgovcEZa34ZkwbbwfXHm2qitHwL2Tpr8p7+PxNhYk=";

  };

  buildInputs = [ gperf openssl readline zlib ];