id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
15867	Document which Python versions show subtle QuerySet bugs	Jacob	nobody	"http://bugs.python.org/issue1242657 continually bites users of Django: see #14766, #2705, #13204, #7786. Also see http://groups.google.com/group/django-developers/browse_thread/thread/cf2b76a9b69f794c/ac09404089bfd185.

The basic problem is that certain versions of Python swallow exceptions in `__len__`, causing various weird QuerySet behaviors. We've mostly worked around these in the test suite by skipping tests on particular Python versions, but this doesn't help users who see weird stuff on their side.

We need to add some sort of ""Python version notes"" document (similar to the [http://docs.djangoproject.com/en/dev/ref/databases/ database notes]) that document this problem (and another others we know of). We should probably also add a link to the install notes to pre-warn people on OSX -- one of the affected versions is the Python that ships with 10.6."	New feature	closed	Documentation	1.3	Normal	wontfix			Accepted	0	1	0	0	0	0