Following the Usual Procedure to install Emacs and AucTeX again, I learned that GNU has changed their repository to use pserver instead of ssh. Yay, it's faster to download now. The proper checkout procedure is now:
[sid@lappy] ~% cvs -z3 -d:pserver:email@example.com:/sources/emacs co emacs
But I think the rest is the same.
Nope, I was wrong. make bootstrap fails:
/usr/bin/ld: Undefined symbols:
It fixed itself! This morning I decided to have another go, and did a cvs up in the emacs project dir... then ./mac/make-package --self-contained worked fine! Thanks GNU developers who updated stuff last night.