Upgrading XFree86-xfs caused the following warning:

# rpm -Uvh XFree86-xfs-4.0.3-1.i386.rpm
grep: /etc/X11/XF86Config-4: No such file or directory

The problem is in the post-install script:

for config in /etc/X11/XF86Config /etc/X11/XF86Config-4 ; do
	...
	if grep -q "unix/:" $config >& /dev/null && \
	...
done

Through /bin/bash, there would not be any problem, but since rpm uses
/bin/sh, I suggest to use the usual syntax:

	if grep -q "unix/:" $config > /dev/null 2>&1 && \