To build the 3.4.9 kernel under amd64 perl is required. I downloaded the stage3 tar ball stage3-amd64-20120621.tar.bz, untarred it, untarred portage.latest.tar.xz and ran emerge --sync && emerge gentoo-sources. Running make fails with: perl: command not found. This is a minor issue as perl can easily be emerged. However, either perl should be added to the stage 3 (preferable) or the documentation should be updated to add this step.
Seems like bug 421483, which is supposedly fixed. Do you have the build flag enabled for gentoo-sources? It must be disabled.
I think I had an old portage directory on /var. I think it must have thought I already had perl installed so didn't pull in the dependency. It worked after I cleaned /var. Sorry - I searched bugzilla but couldn't find the bug you refered to. *** This bug has been marked as a duplicate of bug 421483 ***
