sys-apps/groff-1.19.2-r1 installs /usr/share/doc/groff/1.19.2/ as well as /usr/share/doc/groff-1.19.2-r1. Adding: docdir="${D}/usr/share/doc/${PF}" \ to make install puts everything in /usr/share/doc/groff-1.19.2-r1
thanks, fixed in cvs