To be specific, from the log:
2023-12-03 21:39:19.922 [30721] DirTreeModel.cpp:645 parent(): THROW Exception: Magic number check failed for address 0x58fb8f221ac0

Note that the line number seems to have changed since the Debian version was built. but the location in parent() should be obvious. I can also reproduce it with a build from master.

To reproduce, fairly reliably but not every time:

1. Run a package query on all packages.
2. Open up the tree for one of the packages down to a leaf (I've tried xserver-xorg-core, xserver-xorg, libc6:amd64, mate-themes, and libgl-dev, and crashed them all, but quite a few attempts with firefox-esr didn't crash)
3. Run a filtered package query (eg. "xserver" or "libc6").

It doesn't always crash, but it seems to be much more reliable after opening some packages than others. I don't see what they have in common. Or it might be just packages that I happen to have been looking at.