Comment 1 for bug 1504781

They all get stuck in lxc-test-ubuntu which would indicate either a hang in debootstrap (newly introduced debconf question) or a failure to reach the cloud image server.

In either case, you've not actually regressed LXC, the other tests would have failed if that was the case.

So I'd toss this one over to pitti for investigation and release the updated kernels regardless.