After update, Ubuntu has now become PopOS

Question

I'm running Ubuntu 20.04.1 LTS. I was recently prompted to install an update from Ubuntu's GUI software updater, but I'm not sure which update. Now, I seem to have... a strange amalgamation of Ubuntu and PopOS all of a sudden?

After booting up today, my desktop looks quite different:

• It appears to be using Pop Shell, the tiling window manager that PopOS uses.
• The left-hand dock is gone.
• Looking at 'Appearance -> Background' in Settings, the PopOS wallpapers are present. If I go to 'Appearance -> Appearance', the light/dark theme chooser shows a visual with "Pop!_OS User" in it.
• The scrolling direction has been reversed.
• The icons are different.
• The Ubuntu Software Center is missing, but there's no "Pop Shop" in its place.
• The list goes on...

At the same time, a lot of my system is still very much how it was a few days ago when it was "pure Ubuntu" so to speak. My browser, IDE, files/folders, etc. are all the same...

For context, I used to dual boot Windows and PopOS on a single SSD, but I've since wiped the drives I use (including resetting partitions). Now I use Windows on the SSD and Ubuntu on a new second drive... I can't imagine how anything from my old PopOS installation would carry over, let alone suddenly reappear inside Ubuntu after an update.

EDIT: When running Software Updater again, it shows a full list of what it's trying to install: Software Updater Screenshot. When I try to install these packages, it fails midway through. That partially explains things... but why is this even happening?

EDIT2: It is trying to install pop-gnome-initial-setup.deb which seems to conflict with gnome-initial-setup. Weird.

Solution

You have to purge Pop OS PPA with

sudo apt-get install ppa-purge

sudo ppa-purge ppa:system76/pop

to transform the system back to ordinary Ubuntu. You can use Synaptic to determine left-overs of PopOS and to revert packages to official Ubuntu by specifying their versions.
Manual way is to parse output of saved dpkg -l for pop[0-9] package versions and pop- package names. Be careful with popularity-contest and poppler stuff, they are useful.

---

To get only Popsicle USB flasher you can grab only its packages by

cd ~/Downloads
wget -c https://launchpad.net/~system76/+archive/ubuntu/pop/+files/popsicle_1.3.0~1609365419~20.04~5a49bee_amd64.deb
wget -c https://launchpad.net/~system76/+archive/ubuntu/pop/+files/popsicle-gtk_1.3.0~1609365419~20.04~5a49bee_amd64.deb
sudo apt-get install ./*popsicle*.deb

without adding whole PPA to the system.

Comments

[N0rbert]

Please add output of: cat /etc/os-release, apt-cache policy | grep -i pop, dpkg -l | grep -i pop , grep ^deb -r /etc/apt/ --include=*.list (if long, use pastebin).

[viv]

Thanks for the reply! Output here: pastebin.com/2M44wjyB

[viv]

I have removed the Pop PPA and now Software Updater no longer wants to install a ton of packages. I guess I shouldn't have added it... :v

[Thomas Ward]

Did you try and install PopOS stuf or repos in your system? If you did that'll cause things to conflict like this

[Thomas Ward]

@viv Yeah, the PopOS PPA actually will make your system a chaotic version of PopOS. Which... we don't really support. Only way to really repair is reinstall 'clean'.

[viv]

PopOS has a USB flasher utility that I wanted to use. I clearly didn't understand enough about PPAs to know what I was getting into. Stupid me. :p EDIT: Pop even warns about this on the PPA page: launchpad.net/~system76/+archive/ubuntu/pop WARNING: This PPA is for Pop!_OS, and it may cause breakage on other Ubuntu-based OS's. Use of this repository on non-Pop_OS installations is at your own risk!

[viv]

Thanks for the fix! Lesson learned: Pay attention to warnings. :)

[ChanganAuto]

A more complete answer: askubuntu.com/a/1390854/1210606