Well, I've been checking the log, and I don't think that the problem
affects GCC, because it stops when building libgroff, it says:

/usr/src/gnu/dist/groff/src/libs/libgroff/cmap.cpp:24:18: error: cmap.h:
No such file or directory
nbmkdep: compile failed.

I've also been googling and some users complaint that is always in 
libgroff where it stops, saying that some headers are missing. I can 
compile libgroff manually by doing this:

cd /usr/src/gnu/dist/groff/src/ && make

But, after this, when I run './build.sh -u distribution' it tries to 
rebuild libgroff and fails again. I'm desperate!

Any suggestion I should take?

-- 
Claudio M. Camacho
http://www.claudiocamacho.org