In 2.0.4, @GROFF@ in Makefile.global.in is not substituted, because nothing in configure defines it. As a consequence, the build of the documentation fails. configure contains an unexpanded macro call SLON_AC_PROG_GROFF, which looks like a botched attempt to do groff detection.
Created attachment 51 [details] patch to define GROFF This patch should define GROFF
Looks good to me.
FYI, that seems also to apply to HEAD.
Added to REL_2_0_STABLE and master b4f202e3f67e66a311a4a32c6392bb2be3bc05a2 9dbcd68c88c0add15e242a4f091d2b585bdbae58
I see that in the 2.0 release notes.