Originally reported by: Boris Rybalkin (BitBucket: cyberb, GitHub: cyberb)

Sometimes it is critical to fail when py.test does not find any test. This may happen when you are accidentally running in the wrong directory on the build agent and may lead to the impression that everything is ok.

Something like:
py.test --fail-on-empy

EDIT: fail by default would be even better

• Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/662