Comment 4 for bug 643345

Discussed with Aaron. He says there is no real fix for this; we must have a public email address (real or fake, but selected by the user) that we can pass to bzr as the committer id. That means that we have to let these exports continue to fail, but email the branch owners that they need to set a preferred email address (in the case of users) or contact addresses (in the case of teams).

Most of the problem is likely to be for teams without contact addresses. These will generally be easy to reach regardless.

Team and user addresses are handled separately, but as far as I can tell code that uses Person.preferredemail (as this code does) should pick up a team's contact address as well.