[exim] freebsd 8-beta3 build failure

awk '{ print ($1+1) }' cnumber.h > cnumber.temp
rm -f cnumber.h; mv cnumber.temp cnumber.h
cc version.c
rm -f exim
cc -o exim
lookups/lookups.a(nis.o)(.text+0x14): In function `nis0_find':
: undefined reference to `yp_match'
lookups/lookups.a(nis.o)(.text+0x61): In function `nis_find':
: undefined reference to `yp_match'
lookups/lookups.a(nis.o)(.text+0xae): In function `nis_open':
: undefined reference to `yp_get_default_domain'
*** Error code 1

Stop in /usr/ports/mail/exim/work/exim-4.69/build-FreeBSD-amd64.
*** Error code 1