Buildworld Compile Error - ifmcstat

[hccip at hush.com]

FreeBSD 9.1-RELEASE-p3

===> usr.sbin/ifmcstat (all)
cc -O2 -pipe  -march=nocona -DINET6 -std=gnu99 -fstack-protector -Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized -Wno-pointer-sign -c /usr/src/usr.sbin/ifmcstat/ifmcstat.c
cc1: warnings being treated as errors
/usr/src/usr.sbin/ifmcstat/ifmcstat.c:169: warning: 'in6_ifinfo' used but never defined
*** [ifmcstat.o] Error code 1

Stop in /usr/src/usr.sbin/ifmcstat.
*** [all] Error code 1

I recently removed WITHOUT_IPV6 and WITHOUT_IPV6_SUPPORT from my src.conf - that's why I'm rebuilding world - to get IPv6 support. The custom kernel I am currently running already has INET6. It seems a function definition for ifmcstat is missing somewhere?

Thanks!