Comment 7 for bug 1654025

Haven't yet been dissuaded from that line of thinking:

autopkgtest [11:18:29]: rebooting testbed after setup commands that affected boot
autopkgtest: DBG: sending command to testbed: reboot
autopkgtest-virt-lxd: DBG: executing reboot
[…]
autopkgtest-virt-lxd: DBG: hook_wait_reboot: waiting for container to shut down...
autopkgtest-virt-lxd: DBG: execute-timeout: lxc exec autopkgtest-lxd-mirgzk sleep 3600
autopkgtest-virt-lxd: DBG: hook_wait_reboot: container restarted, waiting for boot to finish
autopkgtest-virt-lxd: DBG: execute-timeout: lxc exec autopkgtest-lxd-mirgzk runlevel
autopkgtest-virt-lxd: DBG: execute-timeout: lxc exec autopkgtest-lxd-mirgzk -- uptime -s
autopkgtest-virt-lxd: DBG: wait_booted: container up since 2017-01-05 11:15:59

I'd expect that last timestamp to be >= 11:18:29