[Grok-dev] Re: AttributeError: type object 'ISessionDataContainer' has no attribute 'isOrExtends'

Philipp von Weitershausen philipp at weitershausen.de
Fri Jun 13 20:18:07 EDT 2008

Peter Bengtsson wrote:
> I tried to copycat the LoginDemo application from grokapps (with some
> slight modifications for my usage)
> But it get this error:
> $ ./bin/zopectl fg
> /home/peterbe/dev/GROK/TheGrokWay/parts/app/runzope -C
> /home/peterbe/dev/GROK/TheGrokWay/parts/zopectl/zope.conf
> Traceback (most recent call last):
> AttributeError: type object 'ISessionDataContainer' has no attribute
> 'isOrExtends'

This has become a FAQ now: you have pickles that refer to 
zope.app.session, but the code was now moved to zope.session. Even 
though zope.app.session has backward-compatibility code for this case, 
your application probably no longer pulls in zope.app.session because it 
has no apparent dependency to that package. Workaround: make your 
application depend on zope.app.session and it should work again.

A similar problem may occur with zope.app.securitypolicy as well.

> I'm using grok 0.12.1 here.

We should release a grok 0.12.2 that fixes this problem by depending on 
zope.app.session and zope.app.securitypolicy again.

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