Can't boot F30 after dnf upgrade from F28. -- Failed to switch root

Please see Red Hat Bugzilla – Bug 1756642 if you have access.

https://bugzilla.redhat.com/show_bug.cgi?id=1756642

After performing a dnf upgrade, the system drops into emergency mode. The error message is

Failed to switch root: Specified switch root path ‘/sysroot’ does not seem to be an OS tree. os-release file is missing.

I verified that /sysroot is empty, I suspect because something is supposed to be mounted there but isn’t. Another user @yogi25 had a similar problem, although i686 instead of x86_64. It doesn’t look like it was resolved. I would try to mount whatever should be there but my drives are all luks devices, so it is not simple from this limited emergency mode to try to manually unlock and mount them. If I boot into the grub emergency mode I am able to unlock and mount them. Same thing if I boot a live image dvd.

Now that F31 is out, I’m afraid no one is going to help with my F30 problem. I’ve been down for 2 months.

I’ve seen similar reports with the same /sysroot error message, but when I looked around the filesystem when I had booted from a live image, it doesn’t look like the same os.release symlink issue. I think it might have to do with decrypting the disks during dracut, but I don’t know enough about dracut to debug this. I do type in my passphrase during boot, but I can’t tell if it is succeeding. I have upladed rdsosreports in the bugzilla.