[Distutils] [proposal] version-free + lookup-friendly dist-info location

[Leonardo Rochael Almeida]

On 17 March 2017 at 07:32, Paul Moore <p.f.moore at gmail.com> wrote:

> On 17 March 2017 at 09:58, Ronny Pfannschmidt <
> opensource at ronnypfannschmidt.de> wrote:
> > [...]
> > in order to address that i'd like to propose to switch
> >
> > from "{distribution}-{version}.dist-info/" to
> "{distribution}.dist-info/"
> >
> > given that it has been used since quite a while i would prefer a quick
> > feedback loop from the ML before thinking about writing a PEP.
>
> +1 from me. And maybe explicitly state that installing multiple
> versions of a distribution is not supported. Although this opens a
> somewhat larger can of worms, in that you can install different
> versions in separate directories - say in system and user
> site-packages - and that has subtle issues but is technically not
> rejected at the moment.


People today rely on being able to install different versions of packages
already installed in other directories. System, vs User site-packages, as
you mentioned is one example.

The `--system-site-packages` switch to `virtualenv` is another. In my
experience, many projects rely on pre-packaged hard-to-build system
packages, while using virtualenv to install more up-to-date versions
project dependencies.

So maybe restrict it to stating that
> installing multiple versions of a distribution *in the same directory*
> is not supported and duck the bigger issue for now.
>

This is already the case everywhere. Even setuptools' `easy_install`, while
capable of installing multiple versions of the same project in the same
site-packages directory, is in reality installing each one to it's own
`.egg` directory inside `site-packages` and can keep only one of
them "active" at a time. ("active" meaning: importable without an explicit
incantation to request a different installed version).

I'm +0 on this proposal (the lack of enthusiasm coming from the fact that
multiple projects will be affected), but I'm -lots on any proposal
forbidding installation of different versions in different directories.

Cheers,

Leo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/distutils-sig/attachments/20170317/3b992b9b/attachment.html>