This is a bug I haven't seen before. It is possible with Linux to describe devices in /etc/fstab with their UUID instead of the device name, i.e.
UUID=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx / ext3 defaults 1 1
instead of
/dev/sda1 / ext3 default 1 1
However, some logic in keg relies on the device starting with a slash to recognize a true-file device. I will have to use a smarter way. This should be a fairly easy fix.