WARN when circ_status_event fails to query Router

import sqlalchemy

import sqlalchemy.orm.exc

from sqlalchemy.orm import scoped_session, sessionmaker, eagerload, lazyload, eagerload_all

from sqlalchemy.orm.exc import NoResultFound

from sqlalchemy import create_engine, and_, or_, not_, func

from sqlalchemy.sql import func,select,alias,case

from sqlalchemy.schema import ThreadLocalMetaData,MetaData

                     last_extend=c.arrived_at)

      if self.track_parent:

        for r in self.parent_handler.circuits[c.circ_id].path:

          try:

            rq = Router.query.options(eagerload('circuits')).filter_by(

                                idhex=r.idhex).with_labels().one()

          except NoResultFound:

            plog("WARN", "Query for Router %s=%s in circ %s failed but was in parent_handler" %

                    (r.nickname, r.idhex, circ.circ_id))

            return;

          circ.routers.append(rq) 

          #rq.circuits.append(circ) # done automagically?

          #tc_session.add(rq)