Comment 7 for bug 1020994

> I've also found an oops without DistroRelease field:
>
> https://errors.ubuntu.com/oops/00834b04-b1a2-11e1-85ef-e4115b0f8a4a
>
> That'd probably cause them not to appear.

Yes, there are a number of crashes in the database that for whatever reason do
not have release fields. The code is mostly careful to step around this by not
trying to use the release field as part of the previously mentioned field
combination:

http://bazaar.launchpad.net/~ev/daisy/trunk/view/head:/utils.py#L24