After upgrading yesterday to various XFree86 4.2.0-2.1 packages, including XFree86-libs, "rpm --verify XFree86-libs" reported that /usr/lib/libGL.so.1 was missing. I can't see anything in the postinstall script for XFree86-libs that would explain why it disappeared, nor does it disappear if I recreate it and then run "ldconfig".
Did you upgrade just _some_ of 4.2.0, or all of it? You can not mix and match packages from 4.1.0 and 4.2.0 if that is what you're doing. libGL is in /usr/X11R6/lib currently. Mesa package is obsoleted.
Here are the XFree86 packages currently on my system; I don't think there are any problems here: XFree86-VGA16-3.3.6-42 XFree86-compat-modules-3.3.6-42 XFree86-Mach64-3.3.6-42 XFree86-libs-4.2.0-2.1 XFree86-4.2.0-2.1 XFree86-twm-4.2.0-2.1 XFree86-devel-4.2.0-2.1 XFree86-100dpi-fonts-4.2.0-2.1 XFree86-75dpi-fonts-4.2.0-2.1 XFree86-tools-4.2.0-2.1 XFree86-doc-4.2.0-2.1 XFree86-xf86cfg-4.2.0-2.1 XFree86-compat-libs-4.0.3-3 XFree86-xfs-4.2.0-2.1 XFree86-Xvfb-4.2.0-2.1 I realize that libGL is in /usr/X11R6/lib, but XFree86-libs-4.2.0-2.1 thinks a there's supposed to be a link to in /usr/lib and that's what was missing after the upgrade: jik:~/build/scripts!6> rpm -q -l -v XFree86-libs | grep /usr/lib/libGL lrwxrwxrwx 1 root root 25 Jan 20 16:24 /usr/lib/libGL.so.1 -> /usr/X11R6/lib/libGL.so.1
This problem appears fixed in current 4.2.0-6.45. Please reopen if you encounter the problem again though. I belive it was fixed a while back, as I recall tweaking the symlinks a bit. Thanks.