[Python-Dev] Packaging and setuptools compatibility

[Alexis Métaireau]

Hi folks,

I have this in my mind since a long time, but I didn't talked about that 
on this list, was only writing on distutils@ or another list we had for 
distutils2 (the fellowship of packaging).

AFAIK, we're almost good about packaging in python 3.3, but there is 
still something that keeps bogging me. What we've done (I worked 
especially on this bit) is to provide a compatibility layer for the 
distributions packaged using setuptools/distribute. What it does, 
basically, is to install things using setuptools or distribute (the one 
present with the system) and then convert the metadata to the new one 
described in PEP 345.

A few things are not handled yet, regarding setuptools: entrypoints and 
namespaces. I would like to espeicially talk about entrypoints here.

Entrypoints basically are a plugin system. They are storing information 
in the metadata and then retrieving them when needing them. The problem 
with this, as everything when trying to get information from metadata is 
that we need to parse all the metadata for all the installed 
distributions. (say O(N)).

I'm wondering if we should support that (a way to have plugins) in the 
new packaging thing, or not. If not, this mean we should come with 
another solution to support this outside of packaging (may be in 
distribute). If yes, then we should design it, and probably make it a 
sub-part of packaging.

What are your opinions on that? Should we do it or not? and if yes, 
what's the way to go?

-- Alexis