gnome-desktop had some recent API changes which are going to impact Unity
https://gitlab.gnome.org/GNOME/gnome-desktop/commit/2882b3e5
https://gitlab.gnome.org/GNOME/gnome-desktop/commit/9d01763b
https://gitlab.gnome.org/GNOME/gnome-desktop/commit/b8e99fc3
The soname changed so we are going to need to fix Unity components for the transition. Could someone in the Unity team look at that? The easiest way might be to just copy the removed APIs to unity-settings-daemon/unity-control-center as needed?
I’ve uploaded gnome-desktop with the API/soname changes in that ppa so you can use the package from there for testing/code porting
https://launchpad.net/~ubuntu-desktop/+archive/ubuntu/transitions,