pacman is the way to go on any Arch based distro. Pamac is a graphical tool to pacman and an AUR/flatpak/snap helper.
//EDIT: also to update you have to read your screens, you can’t update because you have packages that block the update lib32-libcanberra-gstreamer and libcanberra-gstreamer, so remove these package that are now non existent in the repos, and update the system. No need to use other tools, use pacman and read your screens.
Nope, pamac is the cli and pamac-manager is the gui. pacman is cli too. 
Apart this update (That raises major questions to me as forcing pamac) I always use pacman & bauh (that also inclused PWA installs) or Topgrade
I updated using pamac and I didn’t get any preventive information related to this error.
KDE Plasma, kernel 5.10. I had the same message while upgrading via the GUI…reading some of the difficulties encountered on the forum, I immediately cancelled the update procedure…!
Afterwards, I went though Konsole/terminale typing “sudo pamac upgrade”.
Smooth reboot, all is well
For this error, does someone have a clear answer as to what to do?
or a link to the procedure?
can we just delete lib32-libcanberra-gstreamer and libcanberra-gstreamer?
this is my first failed install in a long time although I’ve had unanswered libGL error: MESA-LOADER errors since the previous update.
Yes remove these packages before the update these packages have been removed. The initial post should have cleared that but the info is not in it.
ok thank you, that’s nice and clear 
Two of three computers the update went fine, but on one computer I get a kernel panic on boot:
junk in compressed file archive.
Kernel Panic now, typing from phone. Ok so bad update, what is the solution to this please?
Thank you very much. This worked perfectly! 
Updated with pamac, everything was smooth.
Removing lib32-libcanberra-gstreamer and libcanberra-gstreamer worked just fine and I updated with pacman.
There was a new mkinitcpio.conf pacnew file that required merging but all it added was a zstd compression option.
Not sure if the libcanberra workaround merits an edit of the wiki post so I’ll leave that for somebody else’s discretion.
Still in kernel panic and getting user panic too as I chose stable branch to avoid this kind of thing 
I just tried this Kernel panic message - #3 by Aragorn
Sorry on mobile…
Still stuck in kernel panic, can someone please help?
I’d be interested in a definite answer to that question as well.
Did anyone help you out here? This is the same issue I’m facing
Be patient. I’m sure there will be a solution posted here soon.
Hi,
Did you see this post further up?
I did and tried it but I get :
grub-probe: error: cannot find a GRUB drive for /dev/sdb1. Check your device.map