[Catalog-sig] [Proposal] Registered packages must provide the source code distribution on PyPI

["Martin v. Löwis"]

> I propose a policy change for packages registered with PyPI:
>
>   - packages registered on PyPI have at least one release
>
>   - one release of registered package on PyPI _must_ contain
>     a valid source code distribution (sdist)
>
>   - packages registered on PyPI without releases or without
>     source code release are subject to be removed after N days
>     after the day of registration

So how would you implement that policy change? Please propose a phased 
approach, that gives affected people plenty of options to intervene if
they disagree with the policy.

Regards,
Martin