diff -up lua-5.3.4/src/ldebug.c.bug4 lua-5.3.4/src/ldebug.c --- lua-5.3.4/src/ldebug.c.bug4 2017-08-02 16:05:36.985671687 -0400 +++ lua-5.3.4/src/ldebug.c 2017-08-02 16:05:55.257256062 -0400 @@ -653,6 +653,7 @@ l_noret luaG_runerror (lua_State *L, con CallInfo *ci = L->ci; const char *msg; va_list argp; + luaC_checkGC(L); /* error message uses memory */ va_start(argp, fmt); msg = luaO_pushvfstring(L, fmt, argp); /* format message */ va_end(argp);