[Twisted-Python] Setting a different logger for Twistd

[Landreville]

Hello,
I saw a few tickets and some mailing list messages similar to this
question, but never saw a definitive answer.

How do I go about using a different logger when I am using twistd?

I have a file that defines the application object and I tried the
following code in hopes that I could make the logger have max rotated
logs set to a smaller number:

logfile = LogFile(LOG_FILE, LOG_DIRECTORY, LOG_SIZE, maxRotatedFiles=MAX_LOGS)
application.setComponent(ILogObserver, FileLogObserver(logfile))

but I get an assertion error coming up:
Traceback (most recent call last):
  File "/usr/bin/twistd", line 21, in <module>
    run()
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/twistd.py",
line 27, in run
    app.run(runApp, ServerOptions)
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py",
line 693, in run
    runApp(config)
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/twistd.py",
line 23, in runApp
    _SomeApplicationRunner(config).run()
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py",
line 421, in run
    self.logger.start(self.application)
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py",
line 249, in start
    log.startLoggingWithObserver(self._observer)
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/python/log.py",
line 592, in startLoggingWithObserver
    addObserver(observer)
  File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/python/log.py",
line 253, in addObserver
    assert callable(other)
AssertionError