[Distutils] abstract build system PEP update

[Paul Moore]

On 16 February 2016 at 22:49, Robert Collins <robertc at robertcollins.net> wrote:
> +Being able to create new sdists from existing source trees isn't a thing pip
> +does today, and while there is a PR to do that as part of building from
> +source, it is contentious and lacks consensus. Rather than impose a
> +requirement on all build systems, we are treating it as a YAGNI, and will add
> +such a verb in a future version of the interface if required.

Could we add the following clarification to that?

"""
Currently, however, people using distutils can create sdists using
"setup.py sdist". For other tools, this PEP does not specify how a
sdist should be created, but it does imply that it is sufficient to
make an archive of a source directory, including a "pypa.json" file,
and pip will be able to consume that as a sdist. Whether tools provide
a command to do this is out of scope for this PEP.
"""

Paul.