added additional constraint since errno could be stale
added additional constraint since errno could be stale

thisco-de/nanomsg,snikulov/nanomsg,featherweight/ftw-kernel-nanomsg,reqshark/nanomsg,reqshark/nanomsg,reqshark/nanomsg,thisco-de/nanomsg,featherweight/ftw-kernel-nanomsg,snikulov/nanomsg