// a job control shell and from a shell script.
	setsid();

	if (verbose) {
		printf("calling RunGoroutines\n");
	}

	RunGoroutines();

	// Block SIGIO in this thread to make it more likely that it
	// will be delivered to a goroutine.

	if (verbose) {
		printf("calling pthread_sigmask\n");
	}

	if (sigemptyset(&mask) < 0) {
		die("sigemptyset");
	}

	if (fn == NULL) {
		fprintf(stderr, "%s\n", dlerror());
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		fprintf(stderr, "calling RunGoroutines\n");
	}

	fn();

	// Block SIGIO in this thread to make it more likely that it
	// will be delivered to a goroutine.

	if (verbose) {
		fprintf(stderr, "calling pthread_sigmask\n");
	}

	if (sigemptyset(&mask) < 0) {
		die("sigemptyset");
	}