Thanks to Trevor Johnson, mftrace is now available as native FreeBSD port at ${PORTSDIR}/print/mftrace.
mftrace is a small Python program that lets you trace a TeX bitmap font into a PFA or PFB font (A PostScript Type1 Scalable Font) or TTF (TrueType) font. It is licensed under the GNU GPL.
It supersedes pktrace, which is no longer maintained. See mftrace homepage by Han-Wen Nienhuys for more information.
Since LilyPond 1.9.10 it is mandatory for building the sources.
Install mftrace along with it's dependencies executing(cd /usr/ports/print/mftrace && make all install clean)