just install the GLX tar.gz, maybe they left the
correct symlink out of the rpm....
or make a symlik like this one:
ls /usr/lib/libGL.so -la
lrwxr-xr-x 1 root root 17 Oct 9 23:33 /usr/lib/libGL.so -> libGL.so.1.0.3123
cd to /usr/lib
and issue: ln -s libGL.so.1.0.3123 libGL.so
do ls -la libGL.so and maybe a ldd libGL.so
if there is some output, it should be okay.
after that you can recompile winex.