https://github.com/pypa/pip/issues/986

On Sun, Jun 9, 2013 at 11:21 PM, Lennart Regebro <regebro@gmail.com> wrote:

On Mon, Jun 10, 2013 at 3:37 AM, Jason R. Coombs <jaraco@jaraco.com> wrote:
> I think it would be highly desirable to add support for pip to handle the
> upgrade from distribute 0.6 to 0.7. You’ll note that because 0.7 depends on
> setuptools 0.7 that 0.7 has already been downloaded. Perhaps a shim like you
> propose would work, or it’s also conceivable that distribute 0.7 could
> include a setuptools 0.7 source tree which pip could leverage (but not
> install).

Wild idea: Distribute 0.7 includes a non 2to3 source tree that doesn't
get installed. This would also solve the upgrade issue under Python 3,
and serve as an early test for getting rid of 2to3. :-)

That might then mean that Distribute 0.7 would end up only be pip
ugradeable on Python 2.6 and later, but maybe that's OK? I certainly
don't mind. :-)

//Lennart