[issue23890] assertRaises increases reference counter

Changes by STINNER Victor : -- resolution: -> fixed stage: commit review -> resolved status: open -> closed ___ Python tracker

[issue23890] assertRaises increases reference counter

STINNER Victor added the comment: Thank you Vjacheslav Fyodorov for your bug report! The bug should now be fixed in 3.5, 3.6 and master (future 3.7) branches. Python 2.7 is not affected by the bug. -- ___ Python tracker

[issue23890] assertRaises increases reference counter

STINNER Victor added the comment: New changeset 3dc573c8d19dc42ed786ca3237afdad183c41ca0 by Victor Stinner in branch '3.5': Fix ref cycles in TestCase.assertRaises() (#193) (#2228) https://github.com/python/cpython/commit/3dc573c8d19dc42ed786ca3237afdad183c41ca0 --

[issue23890] assertRaises increases reference counter

Changes by STINNER Victor : -- pull_requests: +2273 ___ Python tracker ___ ___

[issue23890] assertRaises increases reference counter

STINNER Victor added the comment: New changeset 50dbf577e10f806056d60ac956db0748d2cc8257 by Victor Stinner in branch '3.6': bpo-23890: Fix ref cycle in TestCase.assertRaises (#858) https://github.com/python/cpython/commit/50dbf577e10f806056d60ac956db0748d2cc8257 --

[issue23890] assertRaises increases reference counter

STINNER Victor added the comment: It seems like Python 2.7 is not affected. -- ___ Python tracker ___ ___

[issue23890] assertRaises increases reference counter

Changes by STINNER Victor : -- pull_requests: +761 ___ Python tracker ___ ___

[issue23890] assertRaises increases reference counter

STINNER Victor added the comment: New changeset bbd3cf8f1ef1e91a8d6dac6411e18b4b9084abf5 by Victor Stinner in branch 'master': Fix ref cycles in TestCase.assertRaises() (#193) https://github.com/python/cpython/commit/bbd3cf8f1ef1e91a8d6dac6411e18b4b9084abf5 --

[issue23890] assertRaises increases reference counter

Nick Coghlan added the comment: Victor's PR takes a more pragmatic approach to address this problem: rather than adding the ability to clear the frames for an arbitrary exception tree, it just uses a try/finally in a couple of key unittest function definitions to clear the offending circular

[issue23890] assertRaises increases reference counter

Changes by Nick Coghlan : -- stage: needs patch -> commit review ___ Python tracker ___

[issue23890] assertRaises increases reference counter

Changes by STINNER Victor : -- pull_requests: +160 ___ Python tracker ___ ___

[issue23890] assertRaises increases reference counter

Nick Coghlan added the comment: I've been looking into this further, and a reproducer that's independent of assertRaises() is to just bind the function to a local variable name in an outer function: def outer(): callable_obj = f try: callable_obj()

[issue23890] assertRaises increases reference counter

Nick Coghlan added the comment: As Robert noted, this is a straight up error, where the clear_frames() call and deleting the exception traceback from the saved object aren't enough to drop all references to `callable_obj`. The trick is that the cleanup code isn't accounting for __cause__ and

[issue23890] assertRaises increases reference counter

Changes by Subhendu Ghosh : -- nosy: +subho ___ Python tracker ___ ___ Python-bugs-list

[issue23890] assertRaises increases reference counter

Changes by STINNER Victor : -- nosy: +haypo ___ Python tracker ___ ___

[issue23890] assertRaises increases reference counter

Robert Collins added the comment: I don't think we make any guarantees for or against references, but - we attempt to free references already (see how we call clear_frames), so this is a bug, pure and simple. -- ___ Python tracker

[issue23890] assertRaises increases reference counter

Changes by Ezio Melotti : -- assignee: -> docs@python components: +Documentation nosy: +docs@python stage: -> needs patch versions: +Python 3.6 ___ Python tracker

[issue23890] assertRaises increases reference counter

Vjacheslav Fyodorov added the comment: It seems, as a minimum it must be noticed in docs. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue23890 ___

[issue23890] assertRaises increases reference counter

Changes by Ezio Melotti ezio.melo...@gmail.com: -- nosy: +ezio.melotti, michael.foord, rbcollins ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue23890 ___

[issue23890] assertRaises increases reference counter

New submission from Vjacheslav Fyodorov: Sometimes unittest's assertRaises increases reference counter of callable. This can break tests in tricky cases. Not seen in 2.X version. Demo file attached. -- components: Library (Lib) files: test_assertRaises.py messages: 240280 nosy:

[issue23890] assertRaises increases reference counter

R. David Murray added the comment: This is presumably a result of the exception object being saved on the context manager object and there being a circular reference chain that doesn't immediately get GCed. This is just how python works. I don't know if it would be sensible/useful to use the