Comment 3 for bug 686690

FWIW, Benji's comments in bug 686257 describe our expectations.

Given that we were wrong, Martin's suggestion sounds like the right direction to me. We had discussed such an approach earlier, but had hoped it would not be necessary.

I'd very much like anything passing a credentials_file argument to get a deprecation warning. I'd also like something like a deprecation warning if a credentials file is used, but I'm not sure if that is as reasonable. That said, a big concern with both is that these deprecations warn the wrong person, most of the time: users shouldn't have to worry about this. The devs of the code using launchpadlib should.