The Manjaro Plasma Mobile images ship with Discover as the default updater. Unfortunately, system updates through Discover (and hence PackageKit) have had several unresolved issues for the last few months (which were already mentioned deep in various threads):
The stale lockfile. Discover will not actually offer any system update at all until you manually run
sudo rm /var/lib/PackageKit/alpm/db.lck. I believe this is the only reason you do not get more complaints from desperate beginner-level end users about Discover bricking their systems (see below): they just do not see updates at all. This started some time last year, probably when
pacmanwas upgraded to version 6. In another thread, this was claimed to be fixed. It is not. I had it happen again when updating from the previous stable update to the current one last week.
The incomplete updates. This is definitely the worst issue. Discover/PackageKit just skips updating some core packages, which can leave the system in varying states of brokenness. The fix is to run
sudo pacman -Sufrom the CLI to finish the update (refreshing with
-yis normally not even needed), if you even get to run
pacman. Once, I had to actually copy a
pkgfile through USB and install it manually with
NetworkManagerwould work, so that
pacmanwas actually able to download updates. As far as I can tell, this issue started later than the other ones, some time this year. (It first happened for me in March when running the last February update, but I had skipped updates since December. But now, even without skipping updates, it happens basically every time.) When I run
sudo pacman -Sufrom the CLI, it first wants to update the keyring packages, and then proceeds to the remaining update, I think this is what PackageKit does not handle correctly. (I suspect that it does not see the keyring updates and then rejects the others due to being signed with an unknown key. But instead of producing a fatal error as it should in such a case, it just silently skips the updates.) But the partial updates can also leave other stuff in varying states of brokenness, e.g., I twice had the issue that GTK applications were no longer able to display their Adwaita icons (because some cache got corrupted when
gdk_pixbuf2failed to load its libraries), and the resolution was different: last time it happened, I had to reinstall
sudo pacman -S adwaita-icon-theme, this time, I had to
sudo gdk-pixbuf-query-loaders --update-cacheinstead (and each time, the other command had no effect).
The bogus error. This one is a mere annoyance. It happened even when the above issue did not happen, so I believe the error is truly bogus and not PackageKit clumsily trying to report the above to me. Like the first issue, this started some time last year, probably when
pacmanwas upgraded to version 6, and still happened with the latest stable update. After updating, I get a notification from Discover at every boot that the offline update failed until I manually
sudo rm /var/lib/PackageKit/offline-update-competed(sic! They really misspelled
competed!). The offered resolutions do not work: “Open Discover” just opens the Discover UI that does not provide any way to get rid of the error, and “Repair System” is not implemented on Arch/Manjaro at all. There is no “Dismiss” option to make the popups stop permanently (you can close the popup, but it will come back at the next reboot), and there should not be such an unspecific error coming up at each and every update to begin with.
All in all, this leads to a very broken user experience for system updates.