Comment 5 for bug 1484105

@hopem - the case of not setting the machine address should be solved by bug #1537585.

A significant effort was needed to determine that asserting on a struct can fail due to ordering (see the mailing list discussion here: https://lists.ubuntu.com/archives/juju-dev/2016-June/005602.html)

It looks like there may also be a problem with the assertion in SetCharm which could've caused the original problem reported in this bug.