Comment 36 for bug 2043820

> Did you rule out the option of early-install'in systemd-resolved during the upgrade?

My assessment was that this would be too complicated in practice. While there are many mechanisms in the upgrader to *mark* additional packages for installation, there is no good way to say "install this package right now" early in the upgrade. Nor is there a way to change the ordering of packages installed during the upgrade.

The advantage of disabling the stub resolver is that (a) it leaves the apt cache and upgrade calculation alone, and (b) it's a supported mode for systemd-resolved anyways. We're not doing anything tricky; just transiently setting `DNSStubListener=no`.