How to remove Pantheon DE from Ubuntu 16.04?

Question

Can anyone help me remove elementary-desktop? I installed it in my Ubuntu 16.04 LTS x64 system. I already did the "solution" from this question:
How to completely remove Elementary-Desktop from Ubuntu 14.04
and also

sudo apt-get purge elementary-desktop elementary-icon-theme elementary-theme elementary-default-settings

still no luck. I also did

sudo apt-get autoclean elementary-desktop

still didn't do the job. It's still in my system, "elementary OS Desktop" is written in my bar, plus it could still be selected during login.

Btw, I just followed the installation here: How do you install Pantheon on Ubuntu 16.04?

Solution

You used dist-upgrade to install Elementary DE. By doing so, you installed PPA provided versions of packages over standard Ubuntu versions. For example, if Ubuntu provides a nautilus package, and those PPAs provide another nautilus package with higher version, you installed that one.

That's why only removing extra elementary packages such as elementary-desktop, elementary-icon-themes is not sufficient. You have to remove those patched packages too!

So, to completely remove elementary effect, you must go back to Ubuntu versions of packages. To do so, you need ppa-purge. Because only (as a tool to do these things) ppa-purge downgrade packages from PPA versions to Ubuntu versions.

Use these (Change the list according to your usage of PPAs)

sudo ppa-purge ppa:elementary-os/daily
sudo ppa-purge ppa:elementary-os/os-patches
sudo ppa-purge ppa:elementary-os/testing
sudo ppa-purge ppa:mpstark/elementary-tweaks-daily
sudo ppa-purge ppa:elementary-os/stable

To completely get rid of elementary things.

If you don't have ppa-purge already installed, install using

sudo apt-get install ppa-purge

---

Note 1: If you already removed those PPA repository either using sudo apt-add-repository -r or manually editing files, re-add them. Because ppa-purge needs those package list to do the downgrading. After re-adding them, use

sudo apt-get update

command to refresh package index.

Note 2: If you are having an error from ppa-purge saying it can't find aptitude use

sudo apt-get install aptitude

to install it.

Note 3: If ppa-purge fails for some PPAs not being available, remove those PPA entries manually. ppa-purge won't work if every repository doesn't work.

Note 4: If some of PPAs are disabled now (after installing package from them), you have little luck downgrading them automatically. You can identify them and manually downgrade them using synaptic or aptitude. But it's a tedious job.

Note 5: If you still see Elementary session listed on Lightdm, remove pantheon-session package manually.

Notes 6: Remove every extra packages you can identify installed from those PPAs but not available in Ubuntu repositories.

Comments

[afagarap]

I already tried using synaptic, still no luck.

[afagarap]

I already removed those PPAs, can I re-add them? So that I could ppa-purge them?

[Anwar]

Yes. if you didn't use ppa-purge to remove those ppas, re-add them

[afagarap]

After re-adding them, do I still need to do sudo apt-get dist-upgrade?

[Anwar]

No. You should only use sudo apt-get update

[afagarap]

Okay, got it. I'm doing it right now.

[afagarap]

I got this output: darth@darth-Inspiron7559:~$ sudo ppa-purge ppa:elementary-os/daily Updating packages lists W: The repository 'http://ppa.launchpad.net/mpstark/elementary-tweaks-daily/ub‌​untu xenial Release' does not have a Release file. E: Failed to fetch http://ppa.launchpad.net/mpstark/elementary-tweaks-daily/ubu‌​ntu/dists/xenial/mai‌​n/binary-amd64/Packa‌​ges 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead. Warning: apt-get update failed for some reason All through out the end

[Anwar]

OK. some ppas seem to be removed or not available now. I don't know if you used those. anyway, continue using ppa-purge

[afagarap]

You mean, I'll re-run the ppa-purge commands?

[Anwar]

Yes. since some are missing PPAs. remove those ppa entry manually editing the file or removing them and do ppa-purge on rest of the repositories

[afagarap]

I had this error: /usr/sbin/ppa-purge: line 191: aptitude: command not found

[afagarap]

I did all the ppa-purge, repeatedly actually. Still, no luck.

[Anwar]

I don't know how many PPAs actually exists after infecting your machine. If those PPAs aren't exists anymore, you have no luck other than manually identifying every package not from Ubuntu repo, downgrading

[afagarap]

Okay, good news. I successfully removed the elementary-desktop. However, there are two remnants of it: (1) it is still visible as an option in my lightdm, (2) I can't use the shortcut key for my terminal which is Ctrl+Alt+T

[Anwar]

To remove the lightdm entry look for packages named elementary-session or such. remove. And you can re-assign shortcut for terminal

[afagarap]

I searched for elementary-session via synaptic, it didn't find it. As for the shortcut, I have it configured to be called via Ctrl+Alt+T. The thing is, when I'm pressing that shortcut, the terminal is not being called.

[afagarap]

I've deleted the pantheon session, I've read this Q&A: askubuntu.com/questions/81161/…

[afagarap]

As for the shortcut, I made a custom shortcut instead of the shortcut being in the Launcher shortcuts. Thanks very much for the help! :)

[afagarap]

Btw, the ppa-purge was failing at first because of the ppa:mpstark/elementary-tweaks-daily. I removed it using synaptic and tried ppa-purge once again (without the mpstark/elementary-tweaks-daily). It got the job done. Thanks again. :)