This worked for me and might not work for your.
Try it at your own risk!
$ wget -qO - 'http://archive.neon.kde.org/public.key' | sudo apt-key add -
$ sudo apt-add-repository http://archive.neon.kde.org/user
$ sudo apt-get update
$ sudo apt-get install neon-desktop
Upgrade everything. Repeat if necessary, until everything is really up to date and you have no held-back packages.
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade
Thanks for this. I had some minor problems upgrading from Kubuntu 20.04 LTS, but figured it out; Here's what I did in case anyone else encounters the same issue.
Note that once apt has been updated,
sudo apt upgrade
will no longer work, and you will have to usesudo pkcon update
, as is the KDE neon way.Every so often while doing
sudo apt dist-upgrade
,dpkg
would error out, saying a package (from neon) tried to overwrite a file provided by another package (same, already install package from ubuntu), and it won't let you remove the package withsudo apt remove package
. To get around this, for each broken package (I had ~20 in total):sudo dpkg -i --force-overwrite /var/cache/apt/archives/package.deb
(replace path with the one provided by the dpkg error message)sudo apt --fix-broken install -y
sudo apt update && sudo apt dist-upgrade -y
Repeat these steps for every package that breaks in this way, and eventually, the dist-upgrade will go through with no errors. Do another
sudo apt install neon-desktop
andsudo apt autoremove
to make sure everything is up to date. After a reboot, everything booted up without error.