"Mario S. Mommer" <mommer_at_sdf-eu.org> writes:
> checking for rl_completion_matches in -lreadline... yes
> Checking for libfltk.a... yes
> Checking for libX11.a... No, aborting.

I fixed it with (as root)

cd /usr/X11R6/lib && ln -sf /usr/X11R6/lib64/libX11.a

thanks and sorry for the noise.

Regards,
        Mario.