lkl: downgrade to 5.15

stdenv.mkDerivation rec {

  pname = "lkl";

  version = "2023-01-27";

  version = "2022-08-08";

  outputs = [ "dev" "lib" "out" ];

  src = fetchFromGitHub {

    owner  = "lkl";

    repo   = "linux";

    rev  = "b00f0fbcd5ae24636a9315fea3af32f411cf93be";

    sha256 = "sha256-GZpnTVdcnS5uAUHsVre539+0Qlv36Fui0WGjOPwvWrE=";

    rev  = "ffbb4aa67b3e0a64f6963f59385a200d08cb2d8b";

    sha256 = "sha256-24sNREdnhkF+P+3P0qEh2tF1jHKF7KcbFSn/rPK2zWs=";

  };

  nativeBuildInputs = [ bc bison flex python3 ];