+
+ ;; On Linux-based systems, when `ipv6' support is
+ ;; missing (for instance, `ipv6' is loaded and
+ ;; /proc/sys/net/ipv6/conf/all/disable_ipv6 is set
+ ;; to 1), the socket call above succeeds but
+ ;; bind(2) fails like this.
+ ((= errno EADDRNOTAVAIL) (throw 'unresolved))
+