I just had a go at reproducing your problem, on a KDE session that had been running for several days, though with many suspensions.
After killing the X server with ctrl-alt-backspace, the kwin_x11 process went to 100% CPU (on one core), and KDE didn't shut down properly. Trying to log back in, the display got stuck on the splash screen. I conclude that in 20.04, killing an X server with KDE is buggy. Regards, John Little -- -- You received this message from the "vim_dev" maillist. Do not top-post! Type your reply below the text you are replying to. For more information, visit http://www.vim.org/maillist.php --- You received this message because you are subscribed to the Google Groups "vim_dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/vim_dev/b3bf3f13-bf93-4ea9-838e-92219e1c80f2o%40googlegroups.com.
