Digging around /usr/include (trying to figure out why something bombed on me..
I found this:

#if defined(_KERNEL) && !defined(_LKM)
#include "opt_gateway.h"
#endif /* _KERNEL && ! _LKM */

Which causes a build that wants to define _KERNEL to fail.  This seems odd to
me that we would include a file that is never installed.  (I found it in my
compile/RIGEL directory in the sys tree)

This currently is one of the reasons the ucd-snmp pkg fails to build on alpha. 
It seems to declare KERNEL so it can access some private structures and read
from them.  I'm trying to compile it without these defines.. but it still seems
wrong to me to include a file like that...

---
Tim Rightnour    -  root@garbled.net
http://www.zynetwc.com/~garbled/garbled.html