F33 upgrade to F34 hanged

I have started the upgrade to F34 from the Gnome Software. The system rebooted, installation proceeded but hanged at 94%. The console shows

[***] A start job is running for Update the operating system whilst offline (TIME / no limit)

TIME is already > 2h 30m and counting. Is it safe to reboot?

NO !

Never reboot during an update of that sort. Doing so will cause you to do some not-so-easy recovery for the corruption caused (if even possible)

I’m at 4h 55min and out of options…

Well, maybe it is necessary, but still hazardous. I don’t know what all will be required to recover.

@computersavvy you were right, after reboot it failed to boot. I had to do a fresh install.