Unfortunately the upgrade still fails for my CMUCL snapshot (cmucl-2013-04)
I have tried the very recent ASDF:
commit 28a5c936421cdb72b218002c9b207c29bbf592d4
Author: Francois-Rene Rideau <tunes at google.com>
Date: Thu Jan 9 16:58:01 2014 -0500
Bump version to 3.1.0.46