Yesterday's rawhide sunk my iBook

Hi. After applying yesterday's rawhide to my iBook, the system is quite thoroughly toasted. After yum was finished, ssh'ing into the machine no longer worke, and neither did logging in at the local console. Rebooting the machine hangs after the initrd is processed, seemingly failing to execute /sbin/init. My suspicion is that a very low level library is botched (glibc or selinux). Trying to chroot() into the system from an old YDL 3.0 install CD (the only CD what would boot on PPC I found on short notice) fails, just producing segfaults, but YDL 3.0 is quite old, of course, and still running 2.4. Will try and get a FC4 install CD today and try again. PS: The system does not use selinux.