[Distutils] moving things forward

[Leonardo Rochael Almeida]

On 3 May 2016 at 15:07, Alex Grönholm <alex.gronholm at nextday.fi> wrote:

> Having setuptools process the setup requirements before parsing install
> requirements would be a good step forward. Had that been done before, we
> could've just added a setup requirement for a newer setuptools to enable
> PEP 508 conditional requirements.
>

Setuptools does process setup requirements before install requirements. The
"chicken and egg" issue with setuptools is that, most of the time, setup
requires are needed to calculate information that is passed into the
`setup()` call itself.

For example information on header files coming from the C api of `numpy`
which is used to build extensions.

This usually means importing code from the packages in "setup requires"
before setuptools has a chance to actually look at it.

A simple fix would be to allow `setup()` keywords to accept functions as
well as direct values and only invoke the functions when the values are
actually needed, but this idea never gained traction.

Of course, even if this was implemented, it wouldn't help directly with
"setup requiring" a new version of setuptools itself, unless setuptools
detected this situation and reinvoked setup.py from scratch.

Regards,

Leo


03.05.2016, 21:04, Daniel Holth kirjoitti:
>
> We did separate build from install. Now we just want to be able to build
> without [having to emulate] distutils; just having some dependencies
> installed before setup.py runs would also be a great boon.
>
> I'm reading part of this conversation as "a simple bdist_wheel bug is a
> reason to do a lot of work standardizing file formats" which I find
> unfortunate.
>
> If he is still up for it let Robert implement his own PEP as the way
> forward for build system abstraction. The extra PEPs are just delaying
> action.
>
> On Tue, May 3, 2016 at 1:11 PM Paul Moore < <p.f.moore at gmail.com>
> p.f.moore at gmail.com> wrote:
>
>> On 3 May 2016 at 17:47, Donald Stufft <donald at stufft.io> wrote:
>> > It will likely get decided as part of the build system PEP, whenever
>> that
>> > gets picked up again.
>>
>> Yes, but on 15th March
>> (https://mail.python.org/pipermail/distutils-sig/2016-March/028457.html)
>> Robert posted
>>
>> > Just to set expectations: this whole process seems stalled to me; I'm
>> > going to context switch and focus on things that can move forward.
>> > Someone please ping me when its relevant to put effort in again :).
>>
>> And I think that's right. The whole build system PEP issue appears
>> stalled from a lack of someone willing (or with the time) to make a
>> call on the approach we take.
>>
>> As far as I'm aware, the decision remains with Nick. With the possible
>> exception of Donald's proposal (which AFAIK never got formally
>> published as a PEP) everything that can be said on the other proposals
>> has been said, and the remaining differences are ones of choice of
>> approach rather than anything affecting capabilities. (Robert's
>> message at
>> https://mail.python.org/pipermail/distutils-sig/2016-March/028437.html
>> summarised the state of the 3 proposals at the time).
>>
>> I think this is something that should be resolved - we don't appear to
>> be gaining anything by waiting, and until we have a decision on the
>> approach that's being taken, we aren't going to get anyone writing
>> code for their preferred option.
>>
>> Nick - do you have the time to pick this up? Or does it need someone
>> to step up as BDFL-delegate? Robert, Nathaniel, do you have time to
>> spend on a final round of discussion on this, on the assumption that
>> the goal will be a final decision at the end of it? Donald, do you
>> have the time and interest to complete and publish your proposal?
>>
>> Paul
>> _______________________________________________
>> Distutils-SIG maillist  -  Distutils-SIG at python.org
>> https://mail.python.org/mailman/listinfo/distutils-sig
>>
>
>
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>
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