/var was almost full and I ran pacman -Syu and left the comp to go and make dinner. This was also at the time Plasma 6 was rolling out.
It was a big upgrade along with a new kernel. Download seemed to go smoothly, but during installation, it didn’t have enough space to unpack stuff and there was no kernel available to boot. Even the “previous kernel” options didn’t work.
It wasn’t too hard to fix because I had learnt how to use pacman in a chroot env, but my dinner got cold by the time I was ready to eat.
I still haven’t learnt the lesson though. This is the third time I am having a problem with paccache and I still haven’t setup a removal daemon/cron job.