Comment 8 for bug 1538583

This bug is now in 1.25. Since we know the last good commit The suspect commits are:
    https://github.com/juju/juju/commit/e0fc2ca179881c658dc931e15e848707901bd97f
    https://github.com/juju/juju/commit/9f5ca7ef8d0bc60f438e9f44813e1b9701a8a654
    https://github.com/juju/juju/commit/76ca2e226388be4afbd5f40f66ab86e7fafc21de

As none of the commts specifically changes behaviour, we believe one of them changes timing and causes the behaviour change.