static void die(const char* msg) {
	perror(msg);
	exit(EXIT_FAILURE);
}

static volatile sig_atomic_t sigioSeen;

// Use up some stack space.
static void recur(int i, char *p) {
	char a[1024];

	*p = '\0';
	if (i > 0) {
		recur(i - 1, a);
	}
}

// Signal handler that uses up more stack space than a goroutine will have.
static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
	char a[1024];

	recur(4, a);