[Numpy-discussion] Announcing toydist, improving distribution and packaging situation

[David Cournapeau]

On Tue, Dec 29, 2009 at 10:27 PM, René Dudfield <renesd at gmail.com> wrote:

> Buildout is what a lot of the python community are using now.

I would like to note that buildout is a solution to a problem that I
don't care to solve. This issue is particularly difficult to explain
to people accustomed with buildout in my experience - I have not found
a way to explain it very well yet.

Buildout, virtualenv all work by sandboxing from the system python:
each of them do not see each other, which may be useful for
development, but as a deployment solution to the casual user who may
not be familiar with python, it is useless. A scientist who installs
numpy, scipy, etc... to try things out want to have everything
available in one python interpreter, and does not want to jump to
different virtualenvs and whatnot to try different packages.

This has strong consequences on how you look at things from a packaging POV:
 - uninstall is crucial
 - a package bringing down python is a big no no (this happens way too
often when you install things through setuptools)
 - if something fails, the recovery should be trivial - the person
doing the installation may not know much about python
 - you cannot use sandboxing as a replacement for backward
compatibility (that's why I don't care much about all the discussion
about versioning - I don't think it is very useful as long as python
itself does not support it natively).

In the context of ruby, this article makes a similar point:
http://www.madstop.com/ruby/ruby_has_a_distribution_problem.html

David