https://wiki.gentoo.org/wiki/Lua/Porting_notes

--- a/rpc2-src/lua.c
+++ b/rpc2-src/lua.c
@@ -303,10 +303,28 @@ static void l2c_totimeval(lua_State *L, int index, struct timeval *tv)
     }
 }
 
+#if !defined LUA_VERSION_NUM || LUA_VERSION_NUM==501
+/*
+** Adapted from Lua 5.2.0
+*/
+static void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
+  luaL_checkstack(L, nup+1, "too many upvalues");
+  for (; l->name != NULL; l++) {  /* fill the table with given functions */
+    int i;
+    lua_pushstring(L, l->name);
+    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+      lua_pushvalue(L, -(nup+1));
+    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    lua_settable(L, -(nup + 3));
+  }
+  lua_pop(L, nup);  /* remove upvalues */
+}
+#endif
+
 static int l2c_timeval_init(lua_State *L)
 {
     luaL_newmetatable(L, RPC2_TIMEVAL);
-    luaL_openlib(L, NULL, timeval_m, 0);
+    luaL_setfuncs(L, timeval_m, 0);
     lua_register(L, "time", timeval_new);
     return 1;
 }
--- a/configure.ac
+++ b/configure.ac
@@ -55,6 +55,8 @@ AS_IF([test "x$with_libuv" != "xno"],
 
 AC_ARG_WITH(lua,
   [AS_HELP_STRING([--with-lua], [embed Lua interpreter])],
+  [], [with_lua=no])
+AS_IF([test "x$with_lua" != "xno"],
   [PKG_CHECK_EXISTS([lua5.1], [ PKG_CHECK_MODULES([LUA], [lua5.1]) ],
 			       [ PKG_CHECK_MODULES([LUA], [lua]) ])
    AC_DEFINE(USE_LUA, 1, [Define this when linking against Lua])