python -m test color print with and without -j

[MarcinKonowalczyk]

Bug report

Bug description:

./python.exe -m test -j4 prints test results in color. ./python.exe -m test does not. I'm assuming that the -j behaviour is the intended one, as that's the basic instruction in the dev guide.

Having looked at the code, looks like Regrtest::run_tests_sequentially is a tiny bit outdated. I'll submit a PR for consideration in a bit (submitting issue to get an issue number).

Here is an asciinema link demonstrating the behaviour.

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-129363: Added colored printing for python -m test without the -j flag #129364
• gh-129363: Change regrtest sequential mode output #129476
• gh-129363: Change regrtest sequential mode output #129687
• [3.13] gh-129363: Change regrtest sequential mode output (GH-129476) #130405
• [3.12] gh-129363: Change regrtest sequential mode output (GH-129476) #130406

[hugovk]

./python.exe -m test -j4 prints test results in color. ./python.exe -m test does not.

./python.exe -m test does print test results in colour, but it only prints success results for slow tests, so this is technically a feature. More at #129364 (review).

Anyway, this only affects 3.14 so the in practice the distinction doesn't affect bugfix backports :)