Comment 21 for bug 1646739

Actually, I'm not convinced that update-manager is the front end in use here. If we look at the JournalErrors.txt file attached to this bug we can see the following:

dic 02 09:33:40 hostname org.debian.apt[871]: 09:33:40 AptDaemon [INFO]: Initializing daemon
dic 02 09:33:40 hostname org.debian.apt[871]: /usr/lib/python3/dist-packages/aptdaemon/worker/pkworker.py:35: PyGIWarning: PackageKitGlib was imported without specifying a version first. Use gi.require_version('PackageKitGlib', '1.0') before import to ensure that the right version gets loaded.
dic 02 09:33:40 hostname org.debian.apt[871]: from gi.repository import PackageKitGlib as pk

My testing indicates that these errors only appear in the journal when gnome-software is being used and not update-manager.