My nieces were playing (penguin racer i think) on my ppc running debian while it was being upgraded and the machine froze. After turning off I could not reboot into the system.
What to do? I downloaded a ubuntu live ppc disc and I booted into it.
Then I ran a root shell and did
mounted the /dev/hda4 partition which was my root partition.
mount /dev/hda4 /mnt
chroot /mnt /bin/bash
then i still needed to set up a proc directory
so I did
mount -t proc proc /proc
then i did
and then i did
apt-get install -f
and I was able to reboot into the system!!
Yay for debian!