In general checking versions of platforms is not a reliable method. A feature may be added in a
dot release or a patch. It's best to always test the presence of the functionality.
FEN is built on top of the event notification system that exists in Solaris10
so I would suggest a "probe" port_create() with the right FEN parameters and back
off if the create fails.
One other note. If you intend to have a single binary run on multiple versions
of Solaris you should compile it on the oldest version you intend to run on,
e.g. Solaris 10. Executable compiled on a newer OS will as a rule not run on