$OpenBSD: patch-examples_conn-async_c,v 1.1 2016/09/10 13:03:42 ajacoutot Exp $
--- examples/conn-async.c.orig	Sat Sep 10 11:56:38 2016
+++ examples/conn-async.c	Sat Sep 10 11:57:03 2016
@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <sys/select.h> /* fd_set */
 #include <errno.h>
 #include <string.h>
 #include <time.h>