[Python-Dev] PEP 426 is now the draft spec for distribution metadata 2.0

[Nick Coghlan]

On 18 Feb 2013 08:36, "Fred Drake" <fred at fdrake.net> wrote:
>
> On Sun, Feb 17, 2013 at 4:21 PM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> > As Daniel pointed out, easy_install and pip also don't follow this rule
yet,
> > so it won't really have any impact if we never get to metadata 3.0.
>
> Actually, my point was that using a separate filename for version 2.0
would
> allow provision of both 1.x and 2.0, so version 2.0 metadata can be
deployed
> as tool support becomes available, instead of having to wait until 1.x
tools
> are replaced.
>
> Once tools are following the new rule about version compatibility, there's
> less worry about this (at least on my part).

None of sdist, wheel or the installation database currently support
parallel metadata versions. Interpreting 2.0 metadata as 1.1 also won't be
catastrophically wrong in general, especially if the production tools still
also ship the legacy dependency and entry points data as separate files.
The worst thing that is likely to happen is an old tool may fail to show a
2.0 style description.

However, I *will* update the PEP to state explicitly that tools should emit
the lowest required metadata version for the fields being published.

Cheers,
Nick.

>
>
>   -Fred
>
> --
> Fred L. Drake, Jr.    <fred at fdrake.net>
> "A storm broke loose in my mind."  --Albert Einstein
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