Kubuntu-16.04 and updates
The quick “tl;dr” version — updates don’t work, but updating is still possible.
I installed kubuntu-16.04 in April. Although I don’t use it much, I occasionally boot into it to check a few things. Whenever I booted into Kubuntu, I looked to see if the update applet was notifying me of updates. I left the system running for an hour or more, to give it plenty of time to find out.
It never showed any updates.
So I clicked on the applet (hidden tray icon) and asked it to check for updates. It told me that my system was up to date.
I let this slide for a while. But I knew that Canonical had released an updated version of 16.04, so I really was expecting an update.
Earlier this month
When I booted into kubuntu around 2 weeks ago, I decided to check further. It was not reasonable that there had been no update by then.
I first did the same checks as before. Again, I was informed that my system was up to date.
So I fired up “Muon package manager”, which I had installed. I found where to ask it to check for updates. And it found several hundred of them. I installed those updates. I presume this was the update to the revised release of 16.04.
I’ll note that I am booting kubuntu with the grub2 installed by opensuse. The grub2 installed by kubuntu does not work, probably because of the way that I installed in an encrypted LVM. And as I use secure-boot, that meant that I had to add a machine-owner signature to the installed kernel. So kernel updates are a bit of a hassle. Still, that all went fine, and the udpated kubuntu booted without a problem.
I decided to check again today.
Again, the update applet said that my system was up-to-date. The main menu has a system entry “Update Manager”. That also told me that my system was up to date as of milliseconds ago.
Instead of trying “Muon package manager”, this time I tried “Discover”, which was part of the original install. The icon for updates was grayed out. I opened the advanced menu, and there I selected an option to check for updates. It showed a bunch of update (69 as I recall). So I went ahead and applied those.
I still have to add a machine-owner signature to the newly installed kernel, and then see if it boots with the new kernel. I am not expecting problems.
The KDE update applet does not seem to work. If you are running kubuntu 16.04, then be sure to manually check for updates in either “Discover” or “Muon package manager”. You should probably repeat that check every two weeks or so.