sage -t --long --random-seed=286735480429121101562228604801325644303 sage/rings/tests.py
**********************************************************************
File "sage/rings/tests.py", line 453, in sage.rings.tests.?
Failed example:
    test_karatsuba_multiplication(QQbar, 3, 3, numtests=2)    # long time, needs sage.rings.number_field
Expected nothing
Got:
    Random testing has revealed a problem in test_karatsuba_multiplication
    Please report this bug!  You may be the first
    person in the world to have seen this problem.
    Please include this random seed in your bug report:
    Random seed: 327619870453015189736949675324415167773
    ValueError('Multiplication failed')
**********************************************************************
1 item had failures:
   1 of  13 in sage.rings.tests.?
    [62 tests, 1 failure, 1191.47 s]