Hi,
> How do I troubleshoot this? I have no idea what package that was
> updated caused this or even how to find out. It doesn't list any
> specific binary or details on why it failed (that I can tell).
"dnf history info" will give you the list of updates you last did.
Thank you; there were hundreds. "rpm -qva --last" still works too :-)
It turned out the problem was some corrupt ~/.local/gnome-shell entry,
so it worked after removing that directory.