The recommended way to upgrade KDE Neon is with pkcon upgrade. However it seems that most people are unaware of this, if the number of recent complaints about broken Neon upgrades on social media and in #kde-neon are representative. Marco and I also embarrassingly ran afoul of using apt upgrade too.

I recommend that we patch apt itself so that when peoply run apt upgrade or apt full-upgrade, it shows a big blinking red warning message saying something like, "The recommended way to upgrade your KDE Neon system is with pkcon refresh && pkcon upgrade. Using <command> is not supported and can cause breakage."

Otherwise I predict that people will continue to dangerously use apt and we will run into this problem again and again.