New submission from SylvainDe <sylvain.des...@gmail.com>:
Context: -------- Follow-up from https://bugs.python.org/issue35965 which was closed when we assumed the issue was on the coverage side. After nedbat investigation, it seems like the issue comes from call to "sys.settrace". Issue: ------ A test relying on "self.assertRaisesRegex" with raising code "set.add(0)" started to lead to a different error message recently on the CI jobs. Indeed, instead of "descriptor '\w+' requires a 'set' object but received a 'int'" the raised exception was: "descriptor 'add' for 'set' objects doesn't apply to 'int' object" More surprisingly, the behavior was different: - depending on whether "self.assertRaisesRegex" was used as a context manager - on the Python version - when coverage was used. Nedbat was able to pinpoint the root cause for this: the usage of "sys.settrace". This can be hilighted using simple unit-tests: ====================================================================================================== import unittest import sys def trace(frame, event, arg): return trace DESCRIPT_REQUIRES_TYPE_RE = r"descriptor '\w+' requires a 'set' object but received a 'int'" DO_SET_TRACE = True class SetAddIntRegexpTests(unittest.TestCase): def test_assertRaisesRegex(self): if DO_SET_TRACE: sys.settrace(trace) self.assertRaisesRegex(TypeError, DESCRIPT_REQUIRES_TYPE_RE, set.add, 0) def test_assertRaisesRegex_contextman(self): if DO_SET_TRACE: sys.settrace(trace) with self.assertRaisesRegex(TypeError, DESCRIPT_REQUIRES_TYPE_RE): set.add(0) if __name__ == '__main__': unittest.main() ====================================================================================================== Here are the results from the original bug: On some versions, both tests pass: Python 3.6 and before Python 3.7.0a4+ (heads/master:4666ec5, Jan 26 2018, 04:14:24) - [GCC 4.8.4] - ('CPython', 'heads/master', '4666ec5')) On some versions, only test_assertRaisesRegex_contextman fails which was the confusing part: Python 3.7.1 (default, Dec 5 2018, 18:09:53) [GCC 5.4.0 20160609] - ('CPython', '', '') Python 3.7.2+ (heads/3.7:3fcfef3, Feb 9 2019, 07:30:09) [GCC 5.4.0 20160609] - ('CPython', 'heads/3.7', '3fcfef3') On some versions, both tests fail: Python 3.8.0a1+ (heads/master:8a03ff2, Feb 9 2019, 07:30:26) [GCC 5.4.0 20160609] - ('CPython', 'heads/master', '8a03ff2') First analysis: --------------- Using some git bisect magic, I was able to pinpoint the commits leading to each behavior change. - test_assertRaisesRegex_contextman starts to fail from: https://bugs.python.org/issue34126 https://github.com/python/cpython/commit/56868f940e0cc0b35d33c0070107ff3bed2d8766 - test_assertRaisesRegex starts to fail as well from: https://bugs.python.org/issue34125 https://github.com/python/cpython/commit/e89de7398718f6e68848b6340830aeb90b7d582c >From my point of view, it looks like we have 2 regressions. Please let me know >if this needs to be split into 2 independant issues. ---------- files: issue36_git_bisect_script_and_results.txt messages: 335857 nosy: SylvainDe priority: normal severity: normal status: open title: Different error message when sys.settrace is used (regressions) Added file: https://bugs.python.org/file48151/issue36_git_bisect_script_and_results.txt _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36026> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
