weird intermittent error with apache2 and mod_wsgi

Hi All,

Apologies for the cross post, but this problem is occurring with a 
repoze.bfg app running on apache using mod_wsgi, and the exception is 
suggesting something zope.interface related...

So, firstly, it only happens intermittently, and I haven't been able to 
figure out any pattern to the exceptions. It didn't used to happen at 
all (this app has been happily running for a year or so now) but I can't 
think of anything that's changed on the machine in question that might 
cause this. Restarting Apache does appear to cure it for a bit...

The exception is as follows:

File "aircon/bin/mod_wsgi", line 34, in <module>
   from aircon.web import make_app
File "aircon/aircon/web.py", line 2, in <module>
   from aircon.config import system,Session
File "aircon/aircon/config.py", line 1, in <module>
   from gb50 import System
File "aircon/aircon/gb50.py", line 33, in <module>
   class System:
File 
"zope.interface-3.6.1-py2.6-linux-i686.egg/zope/interface/advice.py", 
line 141, in advise
   return callback(newClass)
File 
"zope.interface-3.6.1-py2.6-linux-i686.egg/zope/interface/declarations.py", 
line 471, in _implements_advice
   classImplements(cls, *interfaces)
File 
"zope.interface-3.6.1-py2.6-linux-i686.egg/zope/interface/declarations.py", 
line 447, in classImplements
   spec = implementedBy(cls)
File 
"zope.interface-3.6.1-py2.6-linux-i686.egg/zope/interface/declarations.py", 
line 287, in implementedByFallback
   spec = cls.__dict__.get('__implemented__')
  2011] [error] [client 93.89.128.162] RuntimeError: class.__dict__ not 
accessible in restricted mode

the section of gb50.py looks like:

from aircon.interfaces import ISystem,IUnit
from zope.interface import implements

class System:

     implements(ISystem)

...

The interface is:

from zope.interface import Interface,Attribute

class ISystem(Interface):
...

Anyone seen anything like this before or have any ideas?

cheers,

Chris

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