ZODB 3.10b6 fails to run tests with Python 2.7 on Fedora 14 Branched

[Robin Lee]

I run usually commands to try to test ZODB. But it comes with a strange error:

[cheeselee@chade ZODB3-3.10.0b6]$ bin/test
Running .!no tests here! tests:
  Set up .!no tests here! in 0.001 seconds.
  Ran 1 tests with 0 failures and 0 errors in 0.000 seconds.
Running .BlobAdaptedFileStorageBlobTests tests:
  Tear down .!no tests here! in 0.001 seconds.
  Set up .BlobAdaptedFileStorageBlobTests in 0.001 seconds.
python: /builddir/build/BUILD/Python-2.7/Modules/gcmodule.c:326: visit_decref: Assertion `gc->gc.gc_refs != 0' failed.
Aborted

[Jim Fulton (jim-zope)]

This problem occurs in 3.9 as well and probably in versions back to
2002. It seems to arise from Python's 2.7 (somewhat understandable)
intolerance of ZODB's internal weakref implementation.

I believe this will be fixed by the planned reimplementation of
persistent caches using (subclasses of) standard Python weak refs.

In the mean time, we'll probably declare Python 2.7 to be unsupported.

[Robin Lee (cheeselee)]

Will ZODB 3.10 final support Python 2.7?

[Jim Fulton (jim-zope)]

Unless there is some breakthrough, no.

[Robin Lee (cheeselee)]

And then, Zope 2.13 won't support Python 2.7?

[Hanno Schlichting (hannosch)]

If no current ZODB version can support Python 2.7, then of course no Zope 2 version can support it.

[Jim Fulton (jim-zope)]

There was a breakthrough! :)

Thanks to some help from Tim Peters, I think I'll be able to fix this.
(And get some kind of performance boost as a bonus.)

[Jim Fulton (jim-zope)]

A second breakthrough sealed the deal. Thanks Tim!

for 3.10.0B7.

[Robin Lee (cheeselee)]

All tests of 3.10.0b7 run through now.
Thanks for our developers!