> you should *expect* all those values to persist, so that shouldn't be "surprising".

It's not something I expected, and the warnings around traceback objects are a good indication that other developers have not expected it either. One poster on python-ideas said "Working with traceback objects can easily introduce hidden circular references, so it usually better not access them at all".  Since these 'hidden' references are not used in many cases, it is surprising that they would be required.

> I repeat my recommendation that you take this to python-ideas for feedback, and then work on a patch if the feedback is positive.

I have, and it has been so far.

> (By the way, I checked with a twisted developer, and what he wanted was a convenient way to manually create traceback objects.)

When does Twisted want to manually create traceback objects? Failure has specific functions to stringify the traceback to remove the references mentioned here. Creating a fake traceback would be one way to achieve that, but if the references did not exist I'm not sure what the goal would be.