Description of problem: I rebuild XFree86-4.3.0-50 for the x86_64. The binary packages were placed in a local repository which also had the i386 packages. When I tried to update via up2date, I got an error message that said "XFree86-libs requires libGL.so.1" My solution was to install the i386 version of XFree86-Mesa-libGL. This should be added to the distribution so updates can be performed.
It should be in future trees.