Error page raises NoInteraction

[slinkp]

I get this every so often when stress-testing an almanac page, eg. by doing ab -c 10 -n 100 http://localhost:8181/name-of-almanac
I think it's provoked when a ConflictError still fails after several retries? not sure.

2008-10-30T16:05:32 ERROR SiteError Exception while rendering view on exception
Traceback (most recent call last):
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.app.publication-3.4.3-py2.4.egg/zope/app/publication/zopepublication.py", line 334, in handleException
    body = mapply(view, (), request)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.publisher-3.4.2-py2.4.egg/zope/publisher/publish.py", line 108, in mapply
    return debug_call(obj, args)
   - __traceback_info__: <opengeo.almanac.error.Index object at 0x2f0f538>
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.publisher-3.4.2-py2.4.egg/zope/publisher/publish.py", line 114, in debug_call
    return obj(*args)
  File "/home/pw/builds/geo/almanac/develop-eggs/grok-0.13-py2.4.egg/grok/components.py", line 553, in __call__
    return self.render()
  File "/home/pw/builds/geo/almanac/develop-eggs/grok-0.13-py2.4.egg/grok/components.py", line 536, in render
    self.form_result = self._render_template()
  File "/home/pw/builds/geo/almanac/develop-eggs/grok-0.13-py2.4.egg/grok/components.py", line 176, in _render_template
    return self.template.render(self)
  File "/home/pw/builds/geo/almanac/develop-eggs/grok-0.13-py2.4.egg/grok/components.py", line 381, in render
    return template.pt_render(namespace)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.pagetemplate-3.4.0-py2.4.egg/zope/pagetemplate/pagetemplate.py", line 115, in pt_render
    strictinsert=0, sourceAnnotations=sourceAnnotations)()
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 271, in __call__
    self.interpret(self.program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 891, in do_useMacro
    self.interpret(macro)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 536, in do_optTag_tal
    self.do_optTag(stuff)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 521, in do_optTag
    return self.no_tag(start, program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 516, in no_tag
    self.interpret(program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 891, in do_useMacro
    self.interpret(macro)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 536, in do_optTag_tal
    self.do_optTag(stuff)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 521, in do_optTag
    return self.no_tag(start, program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 516, in no_tag
    self.interpret(program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 957, in do_defineSlot
    self.interpret(block)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 536, in do_optTag_tal
    self.do_optTag(stuff)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 521, in do_optTag
    return self.no_tag(start, program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 516, in no_tag
    self.interpret(program)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 346, in interpret
    handlers[opcode](self, args)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tal-3.4.1-py2.4.egg/zope/tal/talinterpreter.py", line 586, in do_setLocal_tal
    self.engine.setLocal(name, self.engine.evaluateValue(expr))
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tales-3.4.0-py2.4.egg/zope/tales/tales.py", line 696, in evaluate
    return expression(self)
   - /home/pw/builds/geo/almanac/src/CommunityAlmanac/opengeo/almanac/templates/maintemplate.pt
   - Line 49, Column 4
   - Expression: <PathExpr standard:u'context/@@flash-messages'>
   - Names:
      {'args': (),
       'context': <ZODB.POSException.ConflictError instance at 0x52a1190>,
       'default': <object object at 0x2ad9cddaa518>,
       'loop': {},
       'nothing': None,
       'options': {},
       'repeat': {},
       'request': <zc.resourcelibrary.publication.Request instance URL=http://localhost:8181/mherst/voofaaga-/@@index>,
       'static': <grok.components.DirectoryResource object at 0x4fa2c58>,
       'template': <grok.components.TrustedFilePageTemplate object at 0x452a2f8>,
       'view': <opengeo.almanac.error.Index object at 0x2f0f538>}
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tales-3.4.0-py2.4.egg/zope/tales/expressions.py", line 217, in __call__
    return self._eval(econtext)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.tales-3.4.0-py2.4.egg/zope/tales/expressions.py", line 211, in _eval
    return ob()
  File "/home/pw/builds/geo/almanac/develop-eggs/grok-0.13-py2.4.egg/grok/components.py", line 173, in __call__
    return mapply(self.render, (), self.request)
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.publisher-3.4.2-py2.4.egg/zope/publisher/publish.py", line 108, in mapply
    return debug_call(obj, args)
   - __traceback_info__: <bound method FlashMessages.render of <opengeo.almanac.app.FlashMessages object at 0x4983fb8>>
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.publisher-3.4.2-py2.4.egg/zope/publisher/publish.py", line 114, in debug_call
    return obj(*args)
  File "/home/pw/builds/geo/almanac/src/CommunityAlmanac/opengeo/almanac/app.py", line 167, in render
    return [m.message for m in receiver.receive()] + request_msgs
  File "/home/pw/builds/geo/almanac/develop-eggs/z3c.flashmessage-1.0-py2.4.egg/z3c/flashmessage/receiver.py", line 23, in receive
    for message in list(source.list(type)):
  File "/home/pw/builds/geo/almanac/develop-eggs/z3c.flashmessage-1.0-py2.4.egg/z3c/flashmessage/sources.py", line 38, in list
    for message in self._storage:
  File "/home/pw/builds/geo/almanac/develop-eggs/z3c.flashmessage-1.0-py2.4.egg/z3c/flashmessage/sources.py", line 51, in _storage
    request = zope.security.management.getInteraction().participations[0]
  File "/home/pw/builds/geo/almanac/develop-eggs/zope.security-3.4.0-py2.4-linux-x86_64.egg/zope/security/management.py", line 85, in getInteraction
    raise zope.security.interfaces.NoInteraction
NoInteraction