[Zope3-dev] MinimalMemoryStorage test failure in Zope 3

[Tres Seaver]

On Wed, 2003-06-25 at 16:48, Tim Peters wrote:
> >> Marius, which OS and Python version were you using?
> 
> [Marius Gedminas]
> > Debian unstable, Python 2.2.3 (I've tried both the Debian packaged
> > version, and compiled anotjer one myself --with-pydebug).
> 
> Cool -- Debian may be as useful as Win98 <wink>.
> 
> > One machine is a 866 MHz laptop, another one is a 1.something Ghz
> > Athlon.
> >
> > BTW I occasionaly see other errors in the ZODB code as well, for
> > example:
> 
> The actual failures you see are helpful; "for example" doesn't do anything
> to help resolve the ones you don't specifically list, of course.
> 
> > testPackUndoLog (<class
> > 'zodb.storage.tests.test_demo.BasicDemoStorageTests'>) ...
> >
> > Failure in test testPackUndoLog (<class
> > 'zodb.storage.tests.test_demo.BasicDemoStorageTests'>) Traceback
> >   (most recent call last): File
> >     "/home/mg/Zope3/src/zodb/storage/tests/undo.py", line 810, in
> >   testPackUndoLog self.assertEqual(1, len(self._storage.undoLog()))
> >     File "/usr/lib/python2.2/unittest.py", line 286, in
> > failUnlessEqual raise self.failureException,
> > AssertionError: 1 != 0
> 
> That's a bad failure, and should never happen.  It used to fail on Windows
> because of the coarse granularity of time.time() on Windows, but that got
> fixed some time ago.  I never see this one fail anymore.
> 
> With your HW under your OS and BIOS, after
> 
>     x = time.time()
>     y = time.time()
> 
> is it ever the case that
> 
>     x > y
> 
> is true?  For example, some early laptops with "SpeedStep" chips had bugs in
> the BIOS that could cause time to appear to "run backwards" when the chip
> switched cycle rates.  That, or any other, cause for time running backwards
> could also cause any number of sporadic failures in ZODB tests.

NTP, anyone?

Tres.
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Tres Seaver                                tseaver@zope.com
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