We are working to move the default version of GCC in ports (lang/gcc) from GCC 4.8 to GCC 4.9. Sadly this port is one of a few that blocks this update, cf. http://package18.nyi.freebsd.org/data/93amd64-default-PR196712/2015-10-26_13h36m37s/logs/errors/pl-kadu-2.1,1.log An #include <cstdio> or similar may help.
A commit references this bug: Author: pawel Date: Wed Nov 11 15:40:39 UTC 2015 New revision: 401251 URL: https://svnweb.freebsd.org/changeset/ports/401251 Log: - Fix build with gcc 4.9 [1] - Use option helper PR: 204395 [1] Reported by: gerald [1] Changes: head/polish/kadu/Makefile head/polish/kadu/files/patch-kadu-core_execution-arguments_execution-arguments-parser.h