$ adt-run --unbuilt-tree . --- lxd images:ubuntu/xenial/amd64
adt-run [07:21:48]: version 3.19.1
adt-run [07:21:48]: host lindon; command line: /usr/bin/adt-run --unbuilt-tree . --- lxd images:ubuntu/xenial/amd64
<VirtSubproc>: failure: timed out waiting for container adt-virt-lxd-xgopiz to start; last runlevel "unknown
"
adt-run [07:22:59]: ERROR: testbed failure: cannot send to testbed: ['BrokenPipeError: [Errno 32] Broken pipe\n']