Re: master 7f0a252f216 1/2: Prefer python3 for python-interpreter

[Stefan Kangas <stefankangas@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> Yes, they will: we now force them to use Python 3.x, even if they
> point the 'python' symlink to Python 2.x.

To the extent that we "force" anyone with user option defaults, we have
already done that with `python-shell-interpreter'.

> What happens when there's Python 4.x? will we change the value again?

Guido has stated publicly that the Python core team intends to basically
just continue incrementing the minor version until the end of time, and
that there will never be a Python 4.  So, luckily for us, it's not
likely to be an issue for a very long time.

> I'm not saying we should necessarily go back to a single fixed value.
> But we could, for example, test "python" before "python3".  That
> should solve the above case.

OK, then let's do that.  It also seems to be Augusto's preferred option.
It should work on all my machines: let's hope that it works without any
problems elsewhere too.

Assuming that we care about consistency between `python-interpreter' and
`python-shell-interpreter' (I think we should), this means reversing the
decision to prefer Python 3 that was made in Emacs 28.1 (commit
fa686f099800).

So I've now made this change in dd4c67907eb.