Bug report

Bug description:

In Python 3.12+,unittest returns exit code5 when no tests are run and none are skipped. However, if a test class’ssetUpClass() method raises any exception (exceptunittest.SkipTest; related to#106584), no tests are executed, and unittest may incorrectly return exit code5.

This is misleading: the failure occurred due to an error in class-level setup, not because all tests were skipped.

importunittestclassBugTest(unittest.TestCase):@classmethoddefsetUpClass(cls):raiseValueError("Simulated setup failure")deftest_example(self):self.assertTrue(True)

python -m unittest bug_test.pyecho$?

Actual result:

• Exit code is5.

Expected result:

• Exit code should be1, because an error occurred during test setup.

I think we should report the error first, then check whether no tests are run and none are skipped or not.

https://github.com/python/cpython/blob/3.12/Lib/unittest/main.py#L282-L288

Suggested:

ifself.exit:ifnotself.result.wasSuccessful():sys.exit(1)elifself.result.testsRun==0andlen(self.result.skipped)==0:sys.exit(_NO_TESTS_EXITCODE)else:sys.exit(0)

CPython versions tested on:

3.12

Operating systems tested on:

macOS

Linked PRs

• gh-136442: Fix unittest to return exit code 5 when setUpClass raises an exception #136487