[Distutils] Deprecating little used file types/extensions on PyPI?

[Paul Moore]

On 19 August 2016 at 16:14, Donald Stufft <donald at stufft.io> wrote:
> Not sure if we’ll be able to back port it to 2.7 itself, but it’s a trivial
> change to make inside of setuptools as well. Here’s a PR to setuptools that
> will adjust the default: https://github.com/pypa/setuptools/pull/748.

Hmm. So the question becomes, do we care about supporting users
building sdists without setuptools? It's not like this is a scenario
controlled by pip, which auto-injects setuptools. So I guess we'd need
to also publicise the --formats=gztar flag (at
https://packaging.python.org/distributing/#source-distributions if
nowhere else).

So, the plan becomes:

1. Change Python 3.6 to default to .tar.gz on Windows
2. Change setuptoos to default to .tar.gz, to catch users of older versions
3. Document how to create a source distribution as "python setup.py
sdist (add the --formats=gztar flag if you're on Windows and using a
Python older than 3.6 and not using setuptools)" in the PUG
4. Update https://docs.python.org/3/distutils/sourcedist.html for 3.6
to note the change in default.

For (3) soften the laboured conditional comment as much as you like,
but I think we need something to help people who don't understand
what's going on. For (1) and (4), maybe we don't target 3.6 (given
setuptools, it's not urgent) but I think we should change the core, if
only to avoid surprises for people who don't include setuptools in
their setup.py (maybe relying on pip injecting it for things like
wheel builds), and so that distutils isn't (in effect) deliberately
wrong going forward.

> While I think it’s OK to allow .zip in the interim, I do think we should be
> trying to move towards only allowing a single format.

Your arguments are compelling, I have no problem with the conclusion -
we just need a little more thought on the transition.

Paul