HowTo: Upgrade to Ubuntu 19.10 (Eoan Ermine)

Upgrading from Ubuntu 18.04, 18.10, or 19.04 to 19.10 requires a little extra work as a breaking change was introduced to the GNOME code that integrates with i3.

Option 1

1. If the standard Ubuntu session is not installed, install it:
   $ sudo apt install ubuntu-session. (If you have it already installed this should cause no harm.)
2. Perform the upgrade to 19.10.
3. After rebooting, log into the stock Ubuntu session, not Regolith.
4. Re-add the PPA, as the installation process removed it:
   $ sudo add-apt-repository ppa:kgilmer/regolith-stable
5. Upgrade Regolith to the latest version:
   $ sudo apt upgrade
6. Reboot, and now select the Regolith session at the login screen.

Option 2

1. Perform the upgrade to 19.10 but do not reboot after it is finished.
2. Locate the PPA's .list file in /etc/apt/sources.list.d/ directory.
   It's name should be kgilmer-ubuntu-regolith-stable<release name>.list
3. Edit the .list file (with sudo) and remove the heading # from the line beginning with 'deb'. The contents should be:
   deb http://ppa.launchpad.net/kgilmer/regolith-stable/ubuntu eoan main # disabled on upgrade to eoan
# deb-src http://ppa.launchpad.net/kgilmer/regolith-stable/ubuntu eoan main
   
4. Perform update and upgrade to get Eoan version of Regolith packages:
   $ sudo apt update && sudo apt upgrade
5. Reboot and select the Regolith session at the login screen.

NOTE: Some users have reported that regolith-desktop is automatically uninstalled during the upgrade. If this happens, simply run sudo apt install --reinstall regolith-desktop after the upgrade completes to restore the Regolith desktop session.