Implement "finally" with pipelines

[Marko Topolnik]

I have run into another brick wall trying to transform my synchronous long-polling function into an asynchronous one using pipelines. At the end of each request, regardless of outcome, I must schedule some cleanup tasks in case a client doesn't repeat the polling request within a timeout.

Currently I can only see how to handle error and success separately, but no way to provide code that runs unconditionally once the pipeline is realized. Do I have to resort to some kind of duplication, or am I once again overlooking something in the API?

[Zach Tellman]

I've been meaning to add in a :finally clause to the pipeline options
for a while, but haven't yet gotten around to it. Duplication within
the last stage and error-handler is the only way to do that right now.

Zach