Game::setting does not work in debug mode

[fwsGonzo]

inline std::optional<intptr_t> Game::setting(std::string_view setting)
{
	register const char* name_ptr  asm("a0") = setting.begin();
	register unsigned    name_len  asm("a1") = setting.size();
	register long        sysno     asm("a7") = ECALL_GAME_SETTING;
	register bool        has_value asm("a0");
	register intptr_t    result    asm("a1");

	asm("ecall"
		: "=r"(has_value), "=r"(result)
		: "m"(*(const char(*)[name_len])name_ptr),
		  "r"(name_ptr), "r"(name_len), "r"(sysno));

	if (has_value) return int64_t(result);
	return std::nullopt;
}

Looking at this, I cannot see what's wrong. It just doesn't work. Can you see what's wrong?