Attempting to authorize from cron script leads to repeated reauth attempts

Scenario: A cron script want to log in via a pre-existing credentials file that is passed to the login_with() method as the 'credentials_file' parameter. If by mistake that file does not exist, then the call to login_with will attempt to interactively get authorization via the web browser dance.

In launchpadlib/credentials.py the AuthorizeRequestTokenWithBrowser.make_end_authorize_token method is eventually called. It contains this loop:

        while credentials.access_token is None:
            time.sleep(access_token_poll_time)
            try:
                credentials.exchange_request_token_for_access_token(
                    self.web_root)
                break
            except HTTPError, e:
                if e.response.status == 403:
                    # The user decided not to authorize this
                    # application.
                    raise EndUserDeclinedAuthorization(e.content)
                elif e.response.status == 401:
                    # The user has not made a decision yet.
                    pass
                else:
                    # There was an error accessing the server.
                    print "Unexpected response from Launchpad:"
                    print e

The sleep period is 1 second. The loop never gives up. Eventually mthaddon hunts you down and wakes you up at 5 a.m. on a national holiday to ask that you kill your script that is hammering Launchpad.