Spurious warning about not running on main thread

#include <QApplication>
#include <thread>
int main(int argc, char *argv[])
{
	auto gui_wapper = []{
		int nope = 0;
		QApplication a(nope, nullptr);
		QMetaObject::invokeMethod(&a, "quit", Qt::QueuedConnection);
		return a.exec();
	};
	std::thread t1(gui_wapper);
	t1.join();//no spurious warnings, everything works as expected
	std::thread t2(gui_wapper);
	t2.join();//spurious warning, makes me look silly
	return 0;
}