LMDE upgrade broke me

While not strictly an Android issue, I figured I would post this here since it it related to my previously mentioned build box.

Every time LMDE upgrades, it breaks my packages.  At the very least, it breaks the nvidia driver (I should probably switch to source-based) but this last time, it auto uninstalled almost everything NVidia/Gnome/X11/Mate/Cinnamon/etc.

You might be asking, "Why didn't you read the release notes that said to not upgrade yet?"

Well, to be honest, I was used to the simplicity of the daily non-breaking Ubuntu updates.  This new Debian tri-weekly breaking rolling update is a new beast to get used to. I put rolling update in italic because I don't understand how updating more packages less often is 'rolling'.

Anyways, I spent the last 3 days trying to fix my box.  It would boot fine - into a command line... but I really prefer to use Firefox/Chrome/Opera over links to do my web searching.

I am sure these instructions are not the correct way to do things.  You might even say it could be a bad idea to get into someones head.  But since that was the only thing I tried that allowed me to start booting into X again, here we go.

STEP 1:
First off, I determined something I thought should be installed.  I don't know what the process in my head is for that, other than just selecting some random names I thought out to be there.  For example 'gdm'.

STEP 2:
Secondly, I need to find out the correct name for it. IE: it's 'gdm3' not 'gdm'. For this, I did:

apt search gdm

and found the one that looked right (in this case 'gdm3').

STEP 3:
Then, I needed to know whether it was actually installed yet or not -- and at which revision. For that I did:

apt-cache policy gdm3

This showed that it was not currently installed!  Well that doesn't sound right.

STEP 4:
If step 3 showed the correct (updated) candidate:

apt install gdm3

If it fails to install, it might list some unmet dependency.  If so, I start over at STEP 3 (or STEP 2 if that doesn't work) using that dependency as the new name to test.

STEP 5:
If STEP 3 showed the wrong (or no) candidate, I looked at the numbers [priority] at the beginning of each URL.  It might show something like '500' for the one you want to install but '*** 700' for the one you have installed or it wants installed.  Look at the URL for the one with the higher unwanted priority.

STEP 6:
edit /etc/apt/sources.list and comment out the URL from STEP 5

apt update

apt dist-upgrade

Go to STEP 3.


Like I said, these are probably not a good template to follow; however, next time instead of wasting 3 days trying to fix an upgrade I'll start here.