This is happening to me on both the Template and AppVMs based on the template, based on Debian 10 (full, not minimal).
I get the error:
Domain VMNAME has failed to start: Cannot connect to qrexec agent for 60 seconds, see /var/log/xen/console/guest-VMNAME. log for details.
The tail end of the log shows:
[.[0;32m OK .[0m] Started .[0;1;39mAdjust root filesystem size.[0m.
[ 3.722875] xen_netfront: Initialising Xen virtual ethernet driver
[.[0;32m OK .[0m] Found device .[0;1;39m/dev/xvdc1.[0m.
Activating swap .[0;1;39m/dev/xvdc1.[0m...
[.[0;32m OK .[0m] Started .[0;1;39mInitialize and mount /rw and /home.[0m.
[ 3.772247] Adding 1048572k swap on /dev/xvdc1. Priority:-2 extents:1 across:1048572k SSFS
[.[0;32m OK .[0m] Activated swap .[0;1;39m/dev/xvdc1.[0m.
[.[0;32m OK .[0m] Reached target .[0;1;39mSwap.[0m.
[ 3.782616] Error: Driver 'pcspkr' is already registered, aborting...
[ 3.844844] xen_netfront: backend supports XDP headroom
[.[0;32m OK .[0m] Started .[0;1;39mMonitoring of LVM2… dmeventd or progress polling.[0m.
[.[0;32m OK .[0m] Reached target .[0;1;39mLocal File Systems (Pre).[0m.
Mounting .[0;1;39mMount unit for cmake, revision 858.[0m...
Mounting .[0;1;39mMount unit for core18, revision 1997.[0m...
Mounting .[0;1;39mMount unit for cmake, revision 870.[0m...
Mounting .[0;1;39mMount unit for core, revision 10958.[0m...
[.[0;1;31mFAILED.[0m] Failed to mount .[0;1;39mMount unit for cmake, revision 858.[0m.
See 'systemctl status snap-cmake-858.mount' for details.
[.[0;1;31mFAILED.[0m] Failed to mount .[0;1;39mMount unit for core18, revision 1997.[0m.
See 'systemctl status snap-core18-1997.mount' for details.
[.[0;1;31mFAILED.[0m] Failed to mount .[0;1;39mMount unit for cmake, revision 870.[0m.
See 'systemctl status snap-cmake-870.mount' for details.
[.[0;1;31mFAILED.[0m] Failed to mount .[0;1;39mMount unit for core, revision 10958.[0m.
See 'systemctl status snap-core-10958.mount' for details.
You are in emergency mode. After logging in, type "journalctl -xb" to view
system logs, "systemctl reboot" to reboot, "systemctl default" or "exit"
to boot into default mode.
Press Enter for maintenance
I have looked at similar reported issues and tried increasing the initial memory all the way up to 1000MB, but the error and results in the log are the same. I have over 700GB on the Qubes disk available, so space doesn’t seem to be a problem.
I tried restoring several backups of the Template going back to several months ago, but the error is the same on all of them.
I cannot get to a terminal in the TemplateVM or the AppVM so I am at a bit of a loss for further troubleshooting. It looks like everything fails with a Snap.