EDIT: NEW FORMULATION OF THE QUESTION
I have the wrong version of libglib2 installed. I had some experimental repo that broke everything. From this source, https://bugs.launchpad.net/ubuntu/+source/eog/+bug/880227 I have learned that other people have addressed this bug by downgrading the libglib2 package. However, I don't know how to do this.
When I go to synaptic, and search for libglib2, I am met with many packages, rather than just one to downgrade, including:
Which of these gets downgraded for 2.30? All of them? Is one the master?
Secondly, assuming I do choose libglib2.0-0, I face another problem: when I force version, synaptic warns me that the chosen action will affect other packages, and that 14 packages will be removed. These include...
To be removed:
I don't know what most of these are, but I'm fairly sure that ubuntu-desktop and unity are very important, and I don't want them removed. How do I deal with this? Is it safe to proceed in the downgrade even though ubuntu-desktop will be removed? Will it safely and intelligently reinstall and update itself?