I installed kaos today from the 2023.07-x86_64 iso, zfs root filesystem.
I then installed flatpak. This took several goes. Octopi gave me about 10 error messages about not being able to find a file. I ran pkcon -Sy flatpak, which failed and then succeded.
On running flatpak, I saw a error message about not being able to find libarchive.so.20 (from memory, so might have the order of the filename parts wrong). I saw on octopi that libarchive was out of date, but octopi refused to update it (something about a partial update).

So I did a sudo pkcon -Sy libarchive. This worked. Flatpak was happy, and I could install flathub and apps.
But when I restarted and attempted to run pkcon, it gave me an error about not finding libarchive.so.19.
And when I ran Octopi, it silently exited.

I think octopi refused the update because it knew there were a whole bunch of dependent packages also pending update (it was a fresh install, not yet updated).

But, anyway, I'm left with a system with a missing libarchive.so.19, as far as octopi/pkcon is concerned, and nothing I can do to fix it.

Any suggestions? My interest is curiousity-led. If I can't get this to work I'll drop it and play with something else :0)

For pkcon read please pacman - as I said this post was done from memory.