'When a debugger is not found, an error message is printed to the user.'

def test_debuggerNotFound(self):

    def _makeRunner(*args, **kwargs):
        raise trial._DebuggerNotFound('foo')
    self.patch(trial, '_makeRunner', _makeRunner)
    try:
        trial.run()
    except SystemExit as e:
        self.assertIn('foo', str(e))
    else:
        self.fail('Should    have    exited    due    to    non-existent    debugger!')
