Comment 26 for bug 1707400

Detailed instructions on how to use -proposed are here: https://wiki.ubuntu.com/Testing/EnableProposed

To help testing, you could follow the [test case] from the bug in the first comment, confirm the error, and then repeat it fresh but using the package from proposed, and confirm it's fixed.

So, just before the step where it says "install libvirt-bin", you would enable the proposed repository and run "sudo apt update" followed by "sudo apt install libvirt-bin"

A simple way to enable proposed is to just add this line to /etc/apt/sources.list:

deb http://archive.ubuntu.com/ubuntu/ xenial-proposed restricted main multiverse universe

(replace "xenial" with trusty if you are testing on trusty). Then run "sudo apt update". Just DO NOT run "apt upgrade" or "apt dist-upgrade", or accept upgrades offered by your desktop, because the proposed repository contains many other packages that are under testing, not just libvirt.

I suggest to perform the test in a LXD container or virtual machine, so you don't "pollute" your main machine with it.