[Twisted-Python] Strange exception deep in twisted

[Dave Gray]

Matt Feifarek wrote:
> -----------------------
> Unhandled error in Deferred:
> Traceback (most recent call last):
[snip]
>   File "/usr/lib/python2.4/site-packages/twisted/protocols/http.py",
> line 447, in _cleanup
>     self.channel.requestDone(self)
> 
> exceptions.AttributeError: Request instance has no attribute 'channel'

I see errors like these when Deferreds fail and don't handle the error 
somehow and then, later on, get garbage collected. Perhaps this 
exception isn't happening exactly when you think it is?

<http://twisted.sourceforge.net/TwistedDocs-1.3.0/howto/defer.html#auto9>