place diff throws traceback

[paregorios]

Not only does the diff between working copy and baseline not give us useful information, sometimes it just implodes. For example:

Traceback (innermost last):

    Module ZPublisher.Publish, line 138, in publish
    Module ZPublisher.mapply, line 77, in mapply
    Module ZPublisher.Publish, line 48, in call_object
    Module Products.Five.browser.metaconfigure, line 485, in __call__
    Module Products.Five.browser.pagetemplatefile, line 125, in __call__
    Module Products.Five.browser.pagetemplatefile, line 59, in __call__
    Module zope.pagetemplate.pagetemplate, line 132, in pt_render
    Module zope.pagetemplate.pagetemplate, line 240, in __call__
    Module collective.newrelic.patches.talinterpreter, line 17, in monkeypatch
    Module newrelic.api.function_trace, line 112, in literal_wrapper
    Module zope.tal.talinterpreter, line 271, in __call__
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 888, in do_useMacro
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 533, in do_optTag_tal
    Module zope.tal.talinterpreter, line 518, in do_optTag
    Module zope.tal.talinterpreter, line 513, in no_tag
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 954, in do_defineSlot
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 533, in do_optTag_tal
    Module zope.tal.talinterpreter, line 518, in do_optTag
    Module zope.tal.talinterpreter, line 513, in no_tag
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 858, in do_defineMacro
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 954, in do_defineSlot
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 533, in do_optTag_tal
    Module zope.tal.talinterpreter, line 518, in do_optTag
    Module zope.tal.talinterpreter, line 513, in no_tag
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 946, in do_defineSlot
    Module zope.tal.talinterpreter, line 343, in interpret
    Module zope.tal.talinterpreter, line 583, in do_setLocal_tal
    Module zope.tales.tales, line 696, in evaluate
    URL: /srv/python27-apps/pleiades4/eggs/plone.app.iterate-2.1.18-py2.7.egg/plone/app/iterate/browser/diff.pt
    Line 19, Column 2
    Expression: <PathExpr standard:u'view/diffs'>
    Names:

    {'args': (),
     'container': <Place at /plone/places/copy_of_135066932>,
     'context': <Place at /plone/places/copy_of_135066932>,
     'default': <object object at 0xffff9b49f820>,
     'here': <Place at /plone/places/copy_of_135066932>,
     'loop': {},
     'nothing': None,
     'options': {},
     'repeat': <Products.PageTemplates.Expressions.SafeMapping object at 0xffff204cfcb0>,
     'request': <HTTPRequest, URL=https://pleiades.stoa.org/places/copy_of_135066932/@@iterate_diff>,
     'root': <Application at >,
     'template': <Products.Five.browser.pagetemplatefile.ViewPageTemplateFile object at 0xffff3c4b0d50>,
     'traverse_subpath': [],
     'user': <PloneUser 'thomase'>,
     'view': <Products.Five.metaclass.SimpleViewClass from /srv/python27-apps/pleiades4/eggs/plone.app.iterate-2.1.18-py2.7.egg/plone/app/iterate/browser/diff.pt object at 0xffff59925ad0>,
     'views': <Products.Five.browser.pagetemplatefile.ViewMapper object at 0xffff59925d50>}

    Module zope.tales.expressions, line 217, in __call__
    Module Products.PageTemplates.Expressions, line 155, in _eval
    Module Products.PageTemplates.Expressions, line 117, in render
    Module plone.app.iterate.browser.diff, line 30, in diffs
    Module Products.CMFDiffTool.CMFDiffTool, line 156, in createChangeSet
    Module Products.CMFDiffTool.ChangeSet, line 114, in computeDiff
    Module Products.CMFDiffTool.ChangeSet, line 119, in _addSubSet
    Module Products.CMFDiffTool.ChangeSet, line 83, in computeDiff
    Module Products.CMFDiffTool.CMFDiffTool, line 142, in computeDiff
    Module Products.CMFDiffTool.ATCompoundDiff, line 41, in __init__
    Module Products.CMFDiffTool.ATCompoundDiff, line 60, in generateSubDiffs
    Module Products.CMFDiffTool.BaseDiff, line 27, in __init__
    Module Products.CMFDiffTool.BaseDiff, line 78, in _getValue

AttributeError