I did a second reinstallation yesterday evening but then football had kept me in its grip… Sorry!
Today I’ve done the update again by pacman -Syyu (PinePhone USB-connected to a 3.0 jack).
It’s totally reproducible now that one update or a subset of those 257 updates messes up my installation before the update process ends.
In order to narrow down the candidates I took some photos of it:
When
gtk3 update was being installed (or maybe the update immediately after it) a misformed virtual keyboard suddenly folded out, changed several times and began to flicker. At that moment pressing the power key had no effect. About a minute later the (wrong → PC) unlock-session screen appeared. Then it became possible again to turn off and on screen by key. The PinePhone answers ping requests and reacts with the normal sound signal when being unplugged.ssh hasn’t been configured, so it refuses any connection (on standard port 22).
Would it be helpful to get pacman.log from the SD-card and provide it here? Anything else that I could do?