I did a system upgrade from fisher through up2date, following instructions
sent to testers-list, and was left with a non-bootable system.
Up2date upgraded the kernel (and many other things, only left out xemacs
and netscape* due to disk space limitations in /var). Lilo.conf was left
with a stale reference to a vmlinuz-2.4.0-0.99.11 that did not exist
anymore, and I got the wonderfully insightful error message "LI" at boot. :)
There's no mention of any failures in the up2date log, but I can forward
that along if it's requested.
The kernel is included in the up2date skip list for a reason. Taking the
package out of the skip list without understanding the implications and then
blowing away a machine is not a bug. We are in the process of making the kernel
upgrade process less painful, but for the moment, up2date did exactly what you
told it to do and exactly what it would do if you ran 'rpm -ihv' from the