[Catalog-sig] Proposal to Reverse Ordering of Scraped Links in PyPI

[Armin Ronacher]

Hi,

I guess we can all agree on the fact that setuptools/distribute's way to find
packages and package versions is an interesting but unreliable hack.  However
the problem here is that right now many people depend on setuptools and there is
a problem in the combination of setuptools and PyPI and the best way to fix this
is PyPI.

First the problem: setuptools knows the concept of encoding special versions of
packages into URLs in package descriptions.  Many people use that to refer to
development versions.  However if you do that, and the URL changes in a later
version, on the simple index all links will still be present.

In combination with setuptools/distribute's behaviour of using the last match,
this means that you are unable to change the link unless you delete the old
description as well.

As a fix I would recommend just listing the latest links on the simple page or
to reverse the order so that easy_install picks up the right one.
 
Here is an example of such a problematic PyPI item:

  http://pypi.python.org/simple/Flask-Babel/

Obviously, the link to mitsuhiko/flask-sqlalchemy is correct and
USERNAME/REPOSITORY is wrong :)

Is that something that could be changed in PyPI or would that go into a new
version of setuptools/distribute?  Right now it seems like the only solution is
to either delete or edit old entries to fix the links.


Regards,
Armin