Created attachment 227771 [details]
groff moved to ports
The GNU roff toolchain has been removed from base, see /usr/src/UPDATING entry 20170531.
sgmlformat relies on "groff" command to be in PATH and installs three .ts files with references to /usr/share/tmac that does not exist in modern FreeBSD versions.
Attached path adds textproc/groff to RUN_DEPENDS and fixes broken references.