Debian GNU/kFreeBSD is not an officially supported architecture. It has been released with Debian 6.0 (Squeeze) and 7.0 (Wheezy) as a technology preview and the first non-Linux port. Since Debian 8 (Jessie) it is though no more included in official releases.
There's more information about the port (including an FAQ) in the Debian GNU/kFreeBSD wiki page.
#debian-kbsd IRC channel (at irc.debian.org).
Because we use Glibc the portability problems are very simple and most times it's just a matter of copying a test case for "k*bsd*-gnu" from another Glibc-based system (like GNU or GNU/Linux). Look at the porting document for details.
Also look at the TODO file for more details on what needs to be done.
lemon.debian.net (kfreebsd-amd64) is available to Debian developers for porting work. Please see the machine database for more information about these machines. In general, you will be able to use the two chroot environments: testing and unstable. Note that these systems are not administrated by DSA, so do not send requests to debian-admin about it. Instead use firstname.lastname@example.org.