How to debug an autoyast/first-boot problem

I am using autoyast on 13.1 and after autoyast stage 2 runs, the boot sequence stops.
Sometimes a few other start messages come out like the FUSE service,
and/or restoring sound card state, and frequently the last message or two is garbled
like they are missing newlines. Sometimes the autoyast starting stage 2 is the last message.

Once it hangs it is pegging the CPU (as seen in the VM host monitor)
and there are no shells on the virtual consoles.

CAPS-lock is responsive, but virtual console switch is not (tried alt-Fn and ctrl-alt-Fn).

After forcing a reboot, the /var/log/messages file ends in a block of nulls and the last message
is quite a bit older than what I see on the console.
Seems likely the kernel crashed after Yast2 Second Stage ran and the final log bits weren’t written to disk.
I also see D-Bus start errors, which might be a clue.

My autoyast profile is created by “clone this machine” after taking all English defaults (except to have one big partition).
So easy to repro.

I found that installing a minimum system (no graphics) does not have the problem, but that isn’t a useful system.
I suspect that starting the graphical console is where it dies, but it is just a hunch at this point.

Any advice on how to debug this? I want to narrow it down enough to file a bug and/or find a work-around.

Here is /var/log/messages up to the point of the crash:

https://drive.google.com/file/d/0Bx6r5nLbyir7NEoxZEhHZUxXNlE/view?usp=sharing