lua-mpack: fix darwin build

  };

  mpack = buildLuaPackage rec {

    name = "lua-mpack-${version}";

    version = "1.0.7_${rev}";

    rev = "ef025224a799066b818120fb1f30a308543a6e99";

    name = "mpack-${version}";

    version = "1.0.7";

    src = fetchFromGitHub {

      owner = "libmpack";

      repo = "libmpack-lua";

      inherit rev;

      rev = version;

      sha256 = "1nydi6xbmxwl1fmi32v5v8n74msnmzblzqaqnb102w6vkinampsb";

    };

    nativeBuildInputs = [ pkgconfig ];

    buildInputs = [ libmpack ]; # ++ [ libtool lua ];

    buildInputs = [ libmpack ];

    dontBuild = true;

    preInstall = ''

      mkdir -p $out/lib/lua/${lua.luaversion}

      export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:${libmpack}

    postPatch = stdenv.lib.optionalString stdenv.isDarwin ''

      substituteInPlace Makefile \

        --replace '-shared' '-bundle -undefined dynamic_lookup -all_load'

    '';

    NIX_CFLAGS_COMPILE = "-Wno-error -fpic";

    installFlags = [

      "USE_SYSTEM_LUA=yes"

      "USE_SYSTEM_MPACK=yes"

      "MPACK_LUA_VERSION=${(builtins.parseDrvName lua.name).version}"

      "LUA_INCLUDE=-I${lua}/include"

      "LUA_CMOD_INSTALLDIR=$$out/lib/lua/${lua.luaversion}"

      "MPACK_LUA_VERSION=${lua.version}"

      "LUA_CMOD_INSTALLDIR=$(out)/lib/lua/${lua.luaversion}"

    ];

    meta = with stdenv.lib; {