[FDIV018]

Hopefully everybody has noticed this by now.

After install, /usr/include/sys ends up as a link to /usr/sys/sys,
which is a link to /usr/sys/sys.

The files that used to be in /usr/include/sys (or its symlink) appear
to be erased.

Make world cannot be done with the links like this.

If you correct this problem, "make world" will try to change it near the
start of the make "world process" back to the incorrect linking and wlll
change it again a second time at the end of the "make world" process.

Make sure you fix both attempts to scramble links in the "make world" process.

Fix: 

*END*
How-To-Repeat: 
Install complete system.
Try to do a "make world".  After twenty minutes or so it will fail and stop.
When that fails, rm /usr/include/sys and re-extract that directory manually
from the distrbution (if you kept it around).
Now make tar of /usr/include/sys and keep it safe.  You will need it.

Start "make world" again.  About fifteen minutes into the process
before it actually starts compiling anything, verify that /usr/include/sys
is still intact.  Keep checking every few minutes until /usr/include/sys
turns back into the mangled links.  Now ^Z the make.  Extract the tar you
made earlier into /usr/include/sys and let the make world resume.
"Make world" will now complete correctly with no fatal errors.

After "make world" finishes, look at /usr/include/sys and you will
find the files are gone again and the crazy links are back.  Re-extact
the tar you made of /usr/include/sys if you feel energetic.