&mach_exception_handler_port_set);
	if (ret) {
		fprintf(stderr, "runtime/cgo: mach_port_allocate failed for port_set: %d\n", ret);
		abort();
	}

	// Block all signals to the exception handler thread
	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	// Start a thread to handle exceptions.
	uintptr_t port_set = (uintptr_t)mach_exception_handler_port_set;
	pthread_attr_init(&attr);