I have some troubles building NetBSD CURRENT (1.6K) (cvs checkout 
today). The machine is running a NetBSD 1.6 world which has been 
installed from the release sets, and is running a NetBSD 1.6K kernel.

I am building it using the following command-line:

./build.sh -a i386 -B PAIGE -D / -E -m i386 -T 
/usr/src/obj/tools/tools.NetBSD-1.6K-i386 -u

And it breaks with the following output:

PATH=/usr/src/obj/tools/tools.NetBSD-1.6K-i386/lib/groff:${PATH} 
/usr/src/obj/tools/tools.NetBSD-1.6K-i386/bin/nbgroff -Tascii 
-mtty-char -mandoc /usr/src/lib/libc/db/man/btree.3  > btree.cat3.tmp 
&& mv btree.cat3.tmp btree.cat3
/usr/src/obj/tools/tools.NetBSD-1.6K-i386/bin/nbgroff: can't find 
`DESC' file
/usr/src/obj/tools/tools.NetBSD-1.6K-i386/bin/nbgroff:fatal error: 
invalid device `ascii'
Abort trap - core dumped
*** Error code 134

Stop.
nbmake: stopped in /usr/src/lib/libc
*** Error code 1

-- 
  Cliff Albert <cliff@oisec.net>