[Twisted-web] Error output for bad deferred method signatures?

[Lenny G Arbage]

I'm curious why errors aren't reported when deferreds
are fired if the deferred method has a bad signature. 
For example, if the following is run:


import httplib, sys
from twisted.web import client
from twisted.internet import reactor, threads, defer
from twisted.protocols import http
from twisted.python import failure

class getYahoo(object):
    def __init__(self):
        factory =
client.HTTPClientFactory("http://www.yahoo.com")
        reactor.connectTCP("www.yahoo.com",80,factory)
       
factory.deferred.addCallback(self._gotResponse,
factory)
        factory.deferred.addErrback(self._errSendReq,
factory)
        self.deferred = factory.deferred

    def _gotResponse(self, resp, factory):
        print "yeah!"
        print resp

    def _errSendReq(self, err, factory):
        print "shucks!"
        print err

def sendRequest():
    return getYahoo().deferred

if __name__ == '__main__':
    def test(msg):
        print msg
        print respOrErr

    d = sendRequest()
    d.addCallback(test, "success")
    d.addErrback(test, "failure")

    reactor.run()


The deferred _gotResponse() and _errSendReq() fire
perfectly, but the test() function in __main__ is not
called for "success" or "failure".  This is expected
as the signature is wrong -- it should be
'test(respOrErr, msg)'.  What isn't clear [to me] is
why this doesn't produce an error upon firing the
deferred, but instead produces an error when the
reactor shuts down [via ctrl-c], which could be hours
later.

I have an instance of this that is more severe, where
the error output is *never* produced (maybe because of
threading?).

Is this the expected behavior, or am I doing something
atrocious to produce it?

  Thanks,
  Lenny


		
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