Snap Docker builders use apt to get snapcraft which is out of date. Change to use snap download to get it which will get the snap but not need dbus things that Docker misses.
https://github.com/kenvandine/gnome-3-28-1804/blob/master/Dockerfile
collapser.rb in tooling has some relevant code
the chap that wrote the tooling's collapser.rb was right forward-thinking and the implementation of the Unpacker class in there is actually useful to replace most of the stuff going on in that dockerfile.
commit a20bbe2c49e58ec2eb252d6a450cf375b587b9a6 (HEAD -> master, origin/master, origin/HEAD)
Author: Harald Sitter <sitter@kde.org>
Date: Wed Apr 24 12:59:52 2019 +0200
move to snapcraft-from-snap by default
this removes the need for setting no-system-lib and also gives us access
to more suitable snapcraft behavior vis a vis appstream