Here's the situation. You've written your tests. You run your test suite one last time before checking in, and just when you think you are done, you see the big red F indicating test failure.
"Why Me?" you ask. "What now?"
This video discusses strategies for discovering what may have made your test fail, and for exploring what happens during the test run. If you take nothing else away from this video, learn that sometime in the next six months, there's a good chance that git bisect will save you.