[Distutils] extras in PEP-426

[Daniel Holth]

bdist_wheel tries to convert setuptools' own requirements into PEP 426
(draft) json metadata and writes it to .dist-info/. However because
the document is draft the JSON metadata is not used for anything. The
runtime requirements read:

    "run_requires": [
        {
            "extra": "certs",
            "requires": [
                "certifi (==1.0.1)"
            ]
        },
        {
            "environment": "sys_platform=='win32'",
            "extra": "ssl",
            "requires": [
                "wincertstore (==0.2)"
            ]
        }
    ],

On Mon, May 11, 2015 at 6:39 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> On 11 May 2015 at 17:14, Robert Collins <robertc at robertcollins.net> wrote:
>> https://www.python.org/dev/peps/pep-0426/#extras-optional-dependencies
>>
>> Gives an example of:
>>
>> "name": "ComfyChair",
>> "extras": ["warmup", "c-accelerators"]
>> "run_requires": [
>>   {
>>     "requires": ["SoftCushions"],
>>     "extra": "warmup"
>>   }
>> ]
>> "build_requires": [
>>   {
>>     "requires": ["cython"],
>>     "extra": "c-accelerators"
>>   }
>> ]
>>
>>
>> But I am not sure how to map the current setuptools example below to PEP-426:
>>
>> extras_require={
>>     'warmup': ['softcushions', 'barheater'],
>>     'c-accelerators': ['cython', 'barheater'],
>>     }
>>
>> Would we expect multiple build_requires that list barheater, with
>> separate extra lines, in PEP-426?
>>
>> Like so (adjusted to be all run-requires as extra setup-requires
>> aren't a thing in setuptools today):
>> "name": "ComfyChair",
>> "extras": ["warmup", "c-accelerators"]
>> "build_requires": [
>>   {
>>     "requires": ["SoftCushions","barheater"],
>>     "extra": "warmup"
>>   }
>> ]
>> "build_requires": [
>>   {
>>     "requires": ["cython", "barheater"],
>>     "extra": "c-accelerators"
>>   }
>> ]
>>
>> Since build_requires is a key, I'm more than a little confused here.
>> Seems like the extra has to be part of the key, or we're going to be
>> uhm, stuck.
>
> You're close, you just need to rely on the fact that build_requires is
> a sequence rather than a single mapping:
>
> "build_requires": [
>   {
>     "requires": ["SoftCushions","barheater"],
>     "extra": "warmup"
>   },
>   {
>     "requires": ["cython", "barheater"],
>     "extra": "c-accelerators"
>   }
> ]
>
> That's also how you mix unconditional dependencies with conditional
> ones, as well as apply environmental constraints to dependencies
> included in an extra. I don't currently have any examples of mixing
> and matching in the PEP, but it's *already* a monster document :(
>
> Cheers,
> Nick.
>
> --
> Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
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