How to build stable 3.9 branch from fork and clone of cpython

[Chris Angelico]

On Tue, May 18, 2021 at 4:33 PM <pjfarley3 at earthlink.net> wrote:
>
> I am following the "Getting Started" section of the Python Developers Guide,
> but when I build the first version to verify everything builds, it builds
> branch 3.11.
>
>
>
> If I want to build and contribute to branch 3.9, how do I set that up
> please?
>

git checkout 3.9

That should switch you to the branch, replacing all the (tracked)
files in the build directory with the corresponding files from 3.9.

Be aware that most development is going to happen on the master branch
(or the main branch, whichever one you have), and branches like 3.9
are going to get backported patches; so any change you're planning to
contribute to 3.9 is going to need to work correctly on both branches.

ChrisA