Comment 4 for bug 1674317

To verify this... I verified there were no obvious regressions by the
following.
(lxc-proposed-snapshot is
  https://git.launchpad.net/~smoser/cloud-init/+git/sru-info/tree/bin/lxc-proposed-snapshot
It publishes an image to lxd with proposed enabled and cloud-init upgraded.)

$ for r in xenial yakkety; do
   lxc-proposed-snapshot --proposed --publish $r sm0413-$r-proposed; done

$ lxc launch sm0413-xenial-proposed x1674317
$ lxc launch sm0413-xenial-proposed y1674317
$ sleep 30

$ for n in x1674317 y1674317; do
   echo === $n ===
   lxc exec $n -- dpkg-query --show cloud-init
   lxc exec $n cat /run/cloud-init/result.json
   lxc exec $n -- grep WARN /var/log/cloud-init.log || echo no warn
   lxc exec $n -- grep -i traceback /var/log/cloud-init.log || echo no trace
done
=== x1669504 ===

$ for n in x1674317 y1674317; do
> echo === $n ===
> lxc exec $n -- dpkg-query --show cloud-init
> lxc exec $n cat /run/cloud-init/result.json
> lxc exec $n -- grep WARN /var/log/cloud-init.log || echo no warn
> lxc exec $n -- grep -i traceback /var/log/cloud-init.log || echo no trace
> done
=== x1674317 ===
cloud-init 0.7.9-90-g61eb03fe-0ubuntu1~16.04.1
{
 "v1": {
  "datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
  "errors": []
 }
}
no warn
no trace
=== y1674317 ===
cloud-init 0.7.9-90-g61eb03fe-0ubuntu1~16.04.1
{
 "v1": {
  "datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
  "errors": []
 }
}
no warn
no trace