Offline update crash/freeze

I told Fedora to do an offline update last night when I turned my machine off before bed. In the morning, it was still on the “Installing updates” screen, stuck at ninety-something percent done. Hitting Esc or other keys had no effect, so I could not get to the “text mode” with debug info—it seemed like the system was totally frozen and I had to hold the power button to reboot.

(Side note: the debug info normally printed in the “text mode” screen consists only of completion-percentage updates, nothing about what package is being installed or other detailed status. So even if I could access it, there is no valuable information to be found anyway.)

My system seems to be running fine, and sudo dnf update ran without any issues in a live session, so I think I avoided any serious damage. But, this is a pretty concerning event—the last place I want a system crash to happen is in the middle of an update! I have had similar experiences with the offline-updater in the past, too.

I would like to at least identify what caused the crash. I do not see any relevant information in journalctl; am I looking in the wrong place?