the comparison thing was just to see if version numbers matched, I belive. then there was a plan i the help page from there.
blank screen patience. my ctrl+alt+whatever took a lot longer to appear.
you are right about one thing: when it was close to come back to life for me, udisk and nvidia were prominent.
it took a LONG time but the grep command finally worked in TTY. I had to manually remove and reinstall a lot of broken stuff before command worked--I know it goes by fast but I wrote as muc broken down on paper as I could remember. then rdb. then reboot. then after 10 hours FINALLY the login greeter except the wrong one. then boot into a HIDEOUS pitch-black OS called openbox. It's like a pitch black room and the flashlight is the rightclick.
Apparently we nuked our display managers somehow. took forever to get lightdm to work. And budgie itself was gone as well as some necessay gnome apps.
then AFTER grep "fixed" all packages in TTY, I ran the same command in the UI/OS to find more broken. Once that was settled I am back in business with some minor installs.
Coinciding, for me, with the update, is me ripping a lot of programs out this week (for space) without considering deps. That's on me. Then I aborted a 200-package update while SYNCING Friday (accident).
I am whole again.. the reason this reply is so long is there might be on thing you can take away to get you further down the road while my trauma is still fresh🙂
edit/fixed one typo, left the rest...