A regular boot through GRUB (non-recovery) stops around 75 seconds into the dmesg log.
dmesg isn't saved during this process (I see older dmesg logs as
/var/log but not the ones from the failed boot attempts)
From what I can see, there may be the end of a stack trace for Radeon graphics drivers.
This seems to happen right before filesystems are mounted successfully (around 30s), bluetooth initialization (30-32s), and network initialization (32-75s)
There's a few
type 1400 audit(...): apparmor="STATUS" operation="profile_*" ... lines around 63s.
Beyond there, the only changes as I continue to wait are
sky2 0000:03:00.0 eth0: rx error, status 0x402500 length 60 errors which happen even when the system is running successfully. I've found limited information about this error, mainly pointing me to a mailing list about kernel 2.6 issues from years ago with a slightly different status code.
None of the virtual terminals work (just a blinking cursor) and the GUI has not loaded. SSH is not yet running or accessible.
Hitting the power button results in
kvm: exiting hardware virtualization with nothing else happening (no shutdown or further messages other than the sky2 errors every 2 minutes or so).
Holding the power button will hardware shutdown the desktop.
Performing the boot by selecting recovery mode at the GRUB menu and hitting resume allows the system to boot normally, albeit inconveniently since it requires human intervention to boot.
I suspect this might have something to do with either the graphics drivers (open source Radeon -- a recent change from fglrx since latest kernel is not supported by ATI proprietary drivers) or smbd/nmbd which are failing to start (in recovery boot as well, but does not impact boot there).