Issue 36286: Random failure in test_idle (original) (raw)

I have got a failure in test_idle:

0:00:21 load avg: 3.40 [ 76/420/1] test_idle failed test test_idle failed -- Traceback (most recent call last): File "/home/serhiy/py/cpython-clinic/Lib/idlelib/idle_test/test_configdialog.py", line 104, in test_fontlist_key self.assertNotEqual(down_font, font) AssertionError: 'Abyssinica SIL' == 'Abyssinica SIL'

It has not reproduced when run test_idle separately.

I am guessing that test_idle and hence this test have been run over 500 days X 20 runs/day (10000 times) since merged. This is the first report I have seen, though failures that get retested would be masked. My guess is a sporadic timing delay such that the assertion is tested before the widget is updated. Serhiy, does this make sense?

I have reproduced the failure 8 times by running the attached file, derived from test_configdialog, in IDLE. Reps required ranged from about 1000 to 30000, plus I stopped once at nearly 100000 with no failure. About half appeared to be a direct result. All appeared to be an up/down font test, the first of the pair.

Tomorrow, I intend to run this more, including from command line, and then insert update() or update_idletasks() to see if either dependably suppress failure. I am curious what happens on Linux.