Comment 5 for bug 1575903

No, it's not just a "server glitch". OOPS-260df6f569b776ea3899730544ce20fd:

  AttributeError: 'JsonModelNamespaceView' object has no attribute 'publishTraverse'

    Traceback (most recent call last):
  Module zope.publisher.publish, line 129, in publish
    obj = request.traverse(obj)
  Module zope.publisher.browser, line 540, in traverse
    ob = super(BrowserRequest, self).traverse(obj)
  Module zope.publisher.http, line 457, in traverse
    ob = super(HTTPRequest, self).traverse(obj)
  Module zope.publisher.base, line 260, in traverse
    obj = publication.traverseName(self, obj, entry_name)
  Module zope.app.publication.zopepublication, line 194, in traverseName
    ob2 = ob.publishTraverse(request, nm)
AttributeError: 'JsonModelNamespaceView' object has no attribute 'publishTraverse'

This is reproducible with the provided steps when logged out. I'm not sure exactly what's happening as yet, but when you click on "Number" we make an AJAX request to /ubuntu/+bugs/++model++, and that presumably decides somewhere that it isn't usable by anonymous users and redirects to /ubuntu/+bugs/++model++/+login, which doesn't exist.