'If startDebugMode() is called, passing captureVars to Failure() will
not blow up.'

def test_captureVars(self):

    try:
        (1 / 0)
    except:
        (typ, exc, tb) = sys.exc_info()
        f = failure.Failure(captureVars=True)
    self.assertEqual(self.result, [tb])
    self.assertTrue(f.captureVars)
