Comment 5 for bug 1963751

OK, have manually rolled back the system to previous state (the old versions of the packages were still available on my apt-cacher-ng server), and run unattended-upgrades in debug mode - file attached. I guess the key lines are:

sanity check failed for: {'libjavascriptcoregtk-4.0-18=2.34.6-0ubuntu0.20.04.1', 'libopengl0=1.3.2-1~ubuntu0.20.04.1', 'libwebkit2gtk-4.0-37=2.34.6-0ubuntu0.20.04.1'} : pkg libopengl0 is not in an allowed origin
falling back to adjusting libjavascriptcoregtk-4.0-18's dependencies
sanity check failed for: {'nautilus-share=0.7.3-2ubuntu3', 'libjavascriptcoregtk-4.0-18=2.34.6-0ubuntu0.20.04.1', 'gnome-session-flashback=1:3.36.5-0ubuntu1', 'atril=1.24.0-1', 'gnome-todo=3.28.1-5', 'gnucash=1:3.8b-1ubuntu1', 'gnome-calendar=3.36.2-0ubuntu1', 'xubuntu-desktop=2.233', 'ubuntu-unity-desktop=0.2', 'evolution-data-server=3.36.4-0ubuntu1', 'metacity=1:3.36.1-1', 'update-manager=1:20.04.10.7', 'indicator-bluetooth=0.0.6+17.10.20170605-0ubuntu3', 'libfolks-eds25=0.13.2-1', 'gdm3=3.36.3-0ubuntu0.20.04.3', 'update-notifier=3.192.30.7', 'mutter=3.36.9-0ubuntu0.20.04.1', 'gnome-user-docs=3.36.2+git20200704-0ubuntu0.1', 'yelp=3.36.0-1', 'rhythmbox-plugins=3.4.4-1ubuntu2', 'libedataserverui-1.2-2=3.36.4-0ubuntu1', 'libgoa-backend-1.0-1=3.36.0-1ubuntu1', 'ubuntu-session=3.36.0-2ubuntu1', 'ubuntu-docs=20.04.3', 'gir1.2-webkit2-4.0=2.34.6-0ubuntu0.20.04.1', 'libatrilview3=1.24.0-1', 'unity-control-center=15.04.0+19.10.20190921-0ubuntu3', 'gnome-control-center=1:3.36.5-0ubuntu1', 'zenity=3.32.0-5', 'gnome-online-accounts=3.36.0-1ubuntu1', 'ubuntu-release-upgrader-gtk=1:20.04.33', 'gnome-shell=3.36.7-0ubuntu0.20.04.1', 'apturl=0.5.2ubuntu19', 'shotwell=0.30.10-0ubuntu0.1', 'geary=3.36.1-1', 'libyelp0=3.36.0-1', 'libwebkit2gtk-4.0-37=2.34.6-0ubuntu0.20.04.1'} : pkg libgoa-backend-1.0-1 is marked to be deleted

I'm unclear on exactly how u-a is supposed to work, it's possible this is an algorithmic bug there I suppose?