Comment 13 for bug 1575940

If it's easy to reproduce, I'd suggest bootstrapping with --config logging-config='<root>=TRACE' and beta9 from source (if possible, otherwise the released beta8), switching to the controller model, and adding a couple of LXD and LXC (add-machine lxc:0 and lxd:0), reproducing the issue, then attaching the logs from machine 0: /var/log/juju/machine-0.log, /etc/resolv.conf, and /var/log/cloud-init-output.log.