$ ./python -m test -m testRegisterResult test_unittest
Run tests sequentially
0:00:00 load avg: 4.42 [1/1] test_unittest

== Tests result: SUCCESS ==

1 test OK.

Total duration: 98 ms
Tests result: SUCCESS

$ ./python -m test -v -m testRegisterResult test_unittest
== CPython 3.8.0a0 (heads/master-dirty:a801cf164b, Jun 3 2018, 12:58:45) [GCC 7.3.0]
== Linux-4.15.0-22-generic-x86_64-with-glibc2.9 little-endian
== cwd: /home/serhiy/py/cpython/build/test_python_3610
== CPU count: 8
== encodings: locale=UTF-8, FS=utf-8
Run tests sequentially
0:00:00 load avg: 4.17 [1/1] test_unittest
testRegisterResult (unittest.test.test_break.TestBreak) ... FAIL
testRegisterResult (unittest.test.test_break.TestBreakDefaultIntHandler) ... ok
testRegisterResult (unittest.test.test_break.TestBreakSignalDefault) ... ok
testRegisterResult (unittest.test.test_break.TestBreakSignalIgnored) ... ok

======================================================================
FAIL: testRegisterResult (unittest.test.test_break.TestBreak)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/serhiy/py/cpython/Lib/unittest/test/test_break.py", line 48, in testRegisterResult
    self.fail("odd object in result set")
AssertionError: odd object in result set

----------------------------------------------------------------------
Ran 4 tests in 0.002s

FAILED (failures=1)
test test_unittest failed
test_unittest failed

== Tests result: FAILURE ==

1 test failed:
    test_unittest

Total duration: 138 ms
Tests result: FAILURE


The test is passed in 2.7 and 3.4. It fails only starting from 3.5.