tracebacks are obfuscated

Tracebacks, such as those in OOPS-2034AS60 are the site where the exception was re-raised, not the site where it was originally raised. Showing the original site would be clearer in most cases.

  BadStateTransition: Invalid state transition for merge proposal: Superseded -> Approved

    Traceback (most recent call last):
  Module zope.publisher.publish, line 134, in publish
    result = publication.callObject(request, obj)
  Module lazr.restful.publisher, line 211, in callObject
    WebServicePublicationMixin, self).callObject(request, object)
  Module canonical.launchpad.webapp.publication, line 498, in callObject
    return mapply(ob, request.getPositionalArguments(), request)
  Module zope.publisher.publish, line 109, in mapply
    return debug_call(obj, args)
   - __traceback_info__: <security proxied lazr.restful._resource.EntryResource instance at 0x1382d490>
  Module zope.publisher.publish, line 115, in debug_call
    return obj(*args)
  Module lazr.restful._resource, line 943, in __call__
    raise e
BadStateTransition: Invalid state transition for merge proposal: Superseded -> Approved