'L{ConsoleUI.warn} should log a traceback if the output can\'t be opened.'

def test_warnOpenFailed(self):

    def raiseIt():
        (1 / 0)
    ui = ConsoleUI(raiseIt)
    ui.warn('This    message    never    makes    it.')
    self.assertEqual(len(self.flushLoggedErrors(ZeroDivisionError)), 1)
