When upgrading my system it died on /mnt/cdrom saying it could not read it. Unmounting it caused it to die on the floppy. The command it instructed to continue was: ebuild /usr/portage/sys-apps/baselayout/baselayout-1.8.5.7.ebuild merge Unmounting both CDROM and floppy allowed it to finally complete. They are both set to supermount in teh kernel and /etc/fstab.
*** This bug has been marked as a duplicate of 9849 ***