LuaRef::callWithHandler(...).message() returns an invalid message

[3lyrion]

According to this guide I tried to use LuaRef::callWithHandler.

static auto handle = +[](lua_State* L) -> int
{
    luaL_traceback(L, L, NULL, 1);
    std::string trace   = sol::stack::pop<std::string>(L);
    std::string message = $("{}\n{}", lua_tostring(L, 1), trace); // fmt::format
    lua_pushstring(L, message.c_str());
    return 1;
};
auto result = f.callWithHandler(handle, table);
if (!result)
    std::cerr << result.message();

Output:

The lua function invocation raised an error

---

static auto handle = +[](lua_State* L) -> int
{
    luaL_traceback(L, L, NULL, 1);
    std::string trace   = sol::stack::pop<std::string>(L);
    std::string message = $("{}\n{}", lua_tostring(L, 1), trace); // fmt::format
    std::cerr << message;
    lua_pushstring(L, message.c_str());
    return 1;
};
f.callWithHandler(handle, table);

Output:

...lua:18: attempt to index local 'a' (a nil value)
stack traceback:  
        ...
        ...
        ...

[kunitoki]

This might be expected, the Result and TypeResult class don't store the error message from lua to keep it lightweight. If you want to capture the lua error you need to capture it from the handler lambda.