[Distutils] C extension dependencies

[Nick Coghlan]

On 11 September 2014 18:48, Donald Stufft <donald at stufft.io> wrote:
>
> On Sep 11, 2014, at 4:37 AM, Paul Moore <p.f.moore at gmail.com> wrote:
>
> On 11 September 2014 08:15, Donald Stufft <donald at stufft.io> wrote:
>
> Perhaps the gains wouldn’t be worth the complexity though and it’d
> just be easier to allow projects to have a build hint thing that gets
> printed if the build fails.
>
>
> Putting it in core pip sounds to me like a recipe for endless
> system-specific hacks, TBH. Having a plugin system that allowed
> external packages to add (and maintain!) system-specific checks might
> work, but that's pretty complex.
>
> Paul
>
>
> Yes to be specific the only thing I would personally be OK with adding to
> the
> pip core is something that added the appropiate hooks to let some other
> thing
> provide the platform specific mechanisms. I'm still not sure it's worth the
> effort over the simpler idea of just providing a build_hint metadata that
> authors can use to say "Hey you need to isntall libxml2 for this thing" or
> whatever.

It actually occurs to me that the GNU autoconf directory scheme may be
useful here - if people define their dependencies in terms of that
scheme, it should be possible for a plugin to figure out how to ask
the OS installer for them, or otherwise check for them in a virtualenv
or conda environment.

And, if no such plugin is available, the fallback option would be to
just tell the user what's missing.

(FWIW, the only major barrier I see to formalising the metadata 2.0
spec at this point is the lack of up to date jsonschema files. Getting
that out the door may be something to explore post pip 1.6)

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia