@Lanark1982: Nope, something went wrong.
At which point in the update process did it fail? I'd wager ~3/4 of the progress bar?
How much space left do you have on your device?
Which version of the package did you use? The latest release or a snapshot?
If you used one, try the other, and/or if your snapshot wasn't up to date, try the latest.
You don't even need to check if Python works, I have a pretty good idea of what happened. (spoiler: it'll probably work, but you're missing some somewhat important bits).
FWIW, it doesn't actually ask you to reboot the device, it *tells* you that the device will reboot automatically/is rebooting
. Actually playing with the power switch at that point isn't recommended (at all). [Unless they implemented a new specific codepath for this specific error, in which case disregard this].