[Distutils] Metadata 2.0: Is there a formal spec for a requirement?

[Donald Stufft]

> On Sep 16, 2014, at 9:16 PM, Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:
> 
> From: Donald Stufft <donald at stufft.io>
> 
> 
>> Technically that was a PEP 426 change.
> 
> Yes, and I haven't yet changed distlib to remove support for the older "foo (>=X.Y)" form in the earlier version of the PEP.
> 
> 
>> Yea, my “problem” with distlib was always that I think Vinay and I wanted two different things from it. I wanted a
>> reference implementation that only came with the PEP standardized pieces, vinay wanted a library that implemented
>> things he could use for distitil.
> 
> Not quite - it's the other way around: distil is mainly a test bed for distlib, to verify that the latter's functionality is usable in practice. What I want is a rather more modern packaging system than we presently have - for example having to download archives in order to determine dependencies is, shall we say, sub-optimal. I want to move away from setup.py, towards declarative metadata, while offering a migration path (which 3.3 packaging didn't). While they're not perfect, distlib/distil allow me to install stuff without executing setup.py on target systems a lot of the time, and ISTM that's moving things in the right direction.
> 
> Regards,
> 
> Vinay Sajip


I think that’s what we all want, the difference is that myself and some others don’t think it’s acceptable to build ontop of things which aren’t standardized. We’ve had ~15 years of implementation defined “standards”, I don’t think blessing officially something which adds more implementation defined standards is the right path forward. This means that things take longer (It took well over a year for PEP 440, which is just focused around version numbers!) but I think in the end it will end up with a solution that is far more robust and far less likely to end up in a situation where we are today where if you don’t use the exact same tooling as everyone else you’re likely to have problems.

That static metadata is one of the reasons *why* distlib isn’t suitable for the reference implementation. I have no idea if your specific implementation is good, bad, or somewhere in between but afaik there isn’t even a spec at all much less a general discussion about how it should be structured.

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Donald Stufft
PGP: 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA

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