TL;DR, I went to the bottom, clicked the battery icon, and plasma crashed. That's it. No idea what caused it and the bug reporter said there was no useful backtrace generated.
Then we can't do anything. Sorry. (just clicked my battery icon a bunch of times, didn't get anything) Please either install debug symbols or we'll just have to hope that it gets resolved elsewhere.
It seems to be a one-off thing - I haven't seen it happen since either. If it happens again, I'll upload the backtrace anyway despite its uselessness, and perhaps that'll bring something to light. Thank you.