When there's an error, the job seems to hang and doesn't report errors

[tanin47]

I was following this example in here: https://sookocheff.com/post/appengine/mapreduce/mapreduce-yaml/

from mapreduce import operation

def touch(entity):
    """
    Update the entities timestamp.
    """
    yield op.db.Put(entity)

Please notice that op doesn't exist. It should have been operation.

I wonder where I can go see an error if there is one. And why does it hang (on the status page? I had to abort it.

Thank you!