I'm trying to make a catalog of these. Twisted needs to have better-defined exceptions for certain conditions instead of relying on Python to report the error via tracebacks. More specific errors would allow the developer to more quickly track down the problem. Furthermore, programmatic handling of exceptions in the client should be feasible. Handling a TypeError that could be a bug in your code the same as an unauthorized-client-action style error means you have to accept that bugs in your code will be masked if you catch these. Here's the list: 1) cause: Didn't set 'application' in a config.tac. results in this message in the log: "05/02/2002 00:50 [-] Python file '/home/cdodt/TwistedPlugins/dataconda/config.tac' did not produce an application." This isn't gross, but there's no reason not to give more information here. Even though I knew about this requirement, I had forgotten about it and renamed a variable, resulting in this situation. The log message wasn't helpful in reminding me. It should be just a little more specific: "config.tac must set a variable named 'application'. No application was produced." 2) cause: Trying to log in as an Identity that never had a password set Traceback! exceptions.TypeError, argument must be string or read-only buffer, not None /usr/lib/python2.1/site-packages/twisted/spread/pb.py:759:_recvMessage /usr/lib/python2.1/site-packages/twisted/spread/flavors.py:155:remoteMessageReceived /usr/lib/python2.1/site-packages/twisted/spread/pb.py:958:remote_respond /usr/lib/python2.1/site-packages/twisted/cred/identity.py:123:verifyPassword This one is pretty ugly. It's valid to have an Identity with no password. (If it isn't, then you shouldn't be able to create one.) In my case, it just means that user can't log in. If we must throw an exception here, throw "IdentityWithNullPasswordError" or something like that, and better yet, name the identity with the problem. 3) cause: calling a method with the wrong name on a RemoteReferenced object (Perspective, Referenceable, etc.) Traceback! exceptions.AttributeError, LobbyUser instance has no attribute 'perspective_xxx' /usr/lib/python2.1/site-packages/twisted/spread/pb.py:759:_recvMessage /usr/lib/python2.1/site-packages/twisted/spread/pb.py:194:perspectiveMessageReceived Well ok, duh, at least this one I can figure out. But it should still be something more specific: 'RemoteMethodNotImplementedError' for example. I will send more as I find them. Thanks! C __________________________________________________ Do You Yahoo!? Send FREE Valentine eCards with Yahoo! Greetings! http://greetings.yahoo.com