[Distutils] Adding Provides-Extra as an edit to PEP 345

[Erik Bray]

On Mon, Jul 9, 2012 at 10:28 PM, Daniel Holth <dholth at gmail.com> wrote:
> New draft up at https://bitbucket.org/dholth/python-peps/changeset/537e83bd4068
>
> Adds Provides-Extra: (with longer explanation), Setup-Requires-Dist:
> (full text below)
>
> Setup-Requires-Dist lives because it makes sense to list packages only
> needed for setup.py to run before install is possible.
>
> The reserved extra names test and doc live. No one should mind
> installing a distribution and its dependencies in order to run the
> unit tests or generate the documentation.
>
>
> Setup-Requires-Dist (multiple use)
> ::::::::::::::::::::::::::::::::::
>
> Like Requires-Dist, but names dependencies needed while the
> distributions's distutils / packaging `setup.py` / `setup.cfg` is run.
> Commonly used to generate a manifest from version control.
>
> Examples::
>
>     Setup-Requires-Dist: custom_setup_command
>
> Dependencies mentioned in `Setup-Requires-Dist` may be installed
> exclusively for setup and are not guaranteed to be available at run
> time.

+1 To this.  I agree Setup-Requires and Provides-Extra are different
use cases and should both be added to the spec.  I think that filling
in these two missing features will benefit packaging in the long run.
If this idea gains some amount of acceptance I'm happy to work on an
implementation of the setup-requires end of things for packaging.

Erik