Most changes to Pythonrequire a NEWS entry. Add one using theblurb_it web app or theblurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply theskip news label instead.

Most changes to Pythonrequire a NEWS entry. Add one using theblurb_it web app or theblurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply theskip news label instead.

Okay even though this is not an officially documented behavior, it has been like this for a long time and there is some comments in the source code about it. Also it does not cost us too much to revert the behavior back (the old behavior also makes more sense).

In order to prevent cases like this happen in the future, could you also add a quick regression test on it? To make sure changingpdb.line_prefix can change the print out.

Also, even though minor, this still is still a behavior change. You need to add a news entry to it. Click the failedbedevere/news action will guide you to blurbit where you can log in with your github account and add a news entry easily.

Let me know if you are stuck.

Thank you@gaogaotiantian sir for the guidance.
I’ve now added the regression test to ensure that updating pdb.line_prefix at runtime affects the output of print_stack_entry. The test swaps the value using support.swap_attr, calls print_stack_entry(frame, frame.f_lineno), and checks that the custom prefix appears in stdout.
I also added the required news entry

Please let me know if anything needs to be adjusted or improved. Thank you again for your help.❤️

Okay this behavior has been like this since the beginning, at least 25 years ago. However I still don't think it makes sense to be like this. I won't backport this because it's hardly a bug fix and it's definitely not a regression. Let's just silently fix this and keep this as an unsupported undocumented thing.