Code review comment for lp:~ev/ubuntu-ci-services-itself/wider-pyflakes-coverage

I like how elegant this is handling the huge messages (the part that was worrying me most). I've been working on adding tests to this code before actually making such changes, because they are already part of upstream and "only" need to be ported (at least basic unit tests), and that would avoid headaches in case things started to fail because we accidentally changed the logic somewhere. If you agree to hold this for a bit I think I can land tests first, then you can land this branch safely.