We removed official support for NetOS when we started upgrading the inet kit natives for 1.2 and did not have any NetOS resources
to verify that the upgrades worked on that platform. It may still work as-is or with minor tweaks, or it might need major rewriting,
we're just not in a position to say.
If you have NetOS expertise, you can take a look at the natives yourself and see. The #error directive that produces that message
is in inet_util_std.h, you can try removing it and seeing whether the 1.2 code still works with NetOS. If you have trouble, scan through
the inet natives for any place where we compile conditionally for win32 and linux, and see if you can figure out the equivalent changes
to make for NetOS.
Note also that along with the Sedona code, the
sedonadev.org documentation has also been upgraded. The pages on porting
Sedona may be helpful to you in this.