I noticed that MiscTest.test_all in test_traceback.py can be implemented using the new test.support.check__all__. Would it be okay to change it in this pull request?

should ignore_modules go after chain for backwards compatibility? Possibly making it a keyword-only option?

While placing optional boolean arguments after non-boolean ones feels more natural to me, I didn't think about backwards compatibility, so that was an oversight.

That being said, considering the current number of positional arguments that the traceback functions accept, I feel that users should pass optional arguments by their names anyway... Addition of yet another optional argument to several traceback functions seems a good justification for breaking backwards compatibility and making the majority of optional arguments in that module keyword-only. What do you think?

Yes I think that most of them should become keyword only would be the best, then order doesn't matter.

(In the throes of porting some Python code to JavaScript and not having keyword arguments is killing me. :-) so anything to encourage them I like )