Comment 2 for bug 1664437

Here's context from one occurrence:

2017-02-13 22:13:08 DEBUG juju.provisioner.lxd container_initialisation.go:214 Bridging [{DeviceName:bondA BridgeName:br-bondA} {DeviceName:bondM BridgeName:br-bondM}] devices on host "machine-32" with delay=17, acquiring lock "machine-lock"
2017-02-13 22:13:16 INFO juju.utils.packaging.manager utils.go:57 Running: apt-get --option=Dpkg::Options::=--force-confold --option=Dpkg::options::=--force-unsafe-io --assume-yes --quiet install uvtool
2017-02-13 22:13:17 DEBUG juju.provisioner container_initialisation.go:188 release lock "machine-lock" for container initialisation
2017-02-13 22:13:17 DEBUG juju.worker runner.go:178 stop "32-container-watcher"
2017-02-13 22:13:17 DEBUG juju.worker runner.go:235 killing "32-container-watcher"
2017-02-13 22:13:17 DEBUG juju.cmd.jujud machine.go:1527 stopping so killing worker "32-container-watcher"
2017-02-13 22:13:17 INFO juju.worker runner.go:256 start "kvm-provisioner"
2017-02-13 22:13:17 DEBUG juju.worker runner.go:183 "kvm-provisioner" started
2017-02-13 22:13:17 INFO juju.worker runner.go:262 stopped "32-container-watcher", err: <nil>
2017-02-13 22:13:17 DEBUG juju.worker runner.go:190 "32-container-watcher" done: <nil>
2017-02-13 22:13:17 DEBUG juju.worker runner.go:214 no restart, removing "32-container-watcher" from known workers
2017-02-13 22:13:17 INFO juju.provisioner provisioner_task.go:406 found machine pending provisioning id:32/kvm/0, details:32/kvm/0
2017-02-13 22:13:17 INFO juju.provisioner provisioner_task.go:249 provisioner-harvest-mode is set to destroyed; unknown instances not stopped []
2017-02-13 22:13:17 INFO juju.provisioner.kvm kvm-broker.go:66 starting kvm container for containerMachineID: 32/kvm/0
2017-02-13 22:13:17 INFO juju.network bridge.go:70 bridgescript command=/usr/bin/python2 - --interfaces-to-bridge="bondA bondB bondM" --activate --bridge-prefix=br- --reconfigure-delay=17 /etc/network/interfaces <<'EOF'
<script-redacted>
EOF

2017-02-13 22:13:21 INFO juju.network bridge.go:70 bridgescript command=/usr/bin/python2 - --interfaces-to-bridge="bondA bondM" --activate --bridge-prefix=br- --reconfigure-delay=17 /etc/network/interfaces <<'EOF'
<script-redacted>
EOF

2017-02-13 22:13:21 INFO juju.network bridge.go:75 bridgescript result=0, timeout=false
2017-02-13 22:13:57 DEBUG juju.provisioner container_initialisation.go:241 observed network config updated
2017-02-13 22:13:57 DEBUG juju.provisioner.lxd container_initialisation.go:244 releasing lock "machine-lock" for bridging
2017-02-13 22:13:57 DEBUG juju.provisioner.lxd broker.go:108 using multi-bridge networking for container "32/lxd/0"
2017-02-13 22:13:57 WARNING juju.provisioner lxd-broker.go:96 failed to prepare container "32/lxd/0" network config: unable to find host bridge for space(s) "clo", "oam" for container "32/lxd/0"
2017-02-13 22:13:57 WARNING juju.provisioner broker.go:149 incomplete DNS config found, discovering host's DNS config
2017-02-13 22:13:57 DEBUG juju.provisioner broker.go:162 setting DNS servers [public:100.107.64.42] and domains [maas] on container interface "eth0"
2017-02-13 22:13:57 DEBUG juju.tools.lxdclient client.go:203 connecting to LXD remote "cloud-images.ubuntu.com": "https://cloud-images.ubuntu.com/releases"
2017-02-13 22:13:57 INFO juju.tools.lxdclient client_image.go:124 found image from https://cloud-images.ubuntu.com/releases for trusty = 5f19596a09c19d4beed653de08ea438c32e2fee35a10c6963a8285cae95c0a43