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.