HOWTO: Use Sabayon LiveDVD/CD to recover GCC
From Sabayon Wiki
So you did the dreadful thing of unmerging gcc?
The dreadful...
emerge -C gcc
...cue evil music...
Oh...you have the Sabayon LiveDVD/CD? Well you're in luck!
Just use the DVD! No need to download anything or have to make sure it'll just work...you installed the system from Sabayon right? Well it'll work alright Very Happy
Mount your system in /mnt/gentoo
mount /dev/[device-partition] /mnt/gentoo
where [device-partition] is whatever you install gentoo to...e.g. hda1 or sda1
and then:
mount --bind /mnt/gentoo/usr/portage/packages/ /usr/portage/packages/ quickpkg gcc chroot /mnt/gentoo emerge -K gcc