Comment 11 for bug 1416928

I confirmed that manual-provider and 1.21 is indeed broken the same way. With lxc installed on the target state-server:
juju bootstrap
juju ssh 0 "sudo grep -A 1 apiaddresses /var/lib/juju/agents/machine-0/agent.conf"
  apiaddresses:
  - 10.0.3.1:17070