"You have the option of downloading the required tarball from the Internet or, if you booted one of the Gentoo Universal CDs or LiveDVDs, copy it over from the disc itself. If you have a Universal CD or LiveDVD and the stage you want to use is on the disc, downloading it from the Internet is just a waste of bandwidth as the stage files are the same. Minimal CDs and LiveCDs do not contain any stage3 archive, though the LiveDVDs do." There are no stages anymore on the 10.x DVDs. bug 289443 asked for the reinclusion on the DVD which won't happen. So let's fix this the other way around.
Fixed in CVS.