[Distutils] Working toward Linux wheel support

[Chris Barker - NOAA Federal]

> On Jul 17, 2015, at 1:19 PM, Daniel Holth <dholth at gmail.com> wrote:
>
> I've recently packaged SDL2 for Windows as a wheel, without any Python code. It is a conditional dependency "if Windows" for a SDL wrapper.

Cool, though I still think we need wheel-level deps -- the dependency
is on the particular binary, not the platform. But a good start.

>
> We were talking on this list about adding more categories to wheel, to make it easier to install in abstract locations "confdir", "libdir" etc. probably per GNU convention which would map to /etc, /usr/share, and so forth based on the platform.

Where would the concrete firs be? I think inside the Python install
I.e. Where everything is managed by python . I don't think I want pip
dumping stuff in /use/local, nevermind /usr. And presumably the goal
is to support virtualenv anyway.

> Someone needs to write that specification. Propose we forget about Windows for the first revision, so that it is possible to get it done.

If we want Windows support in the long run -- and we do -- we should
be thinking about it from the start. But if it's going in the
Python-managed dirs, it doesn't have to follow Windows convention ...

> The real trick is when you have to depend on something that lives outside of your packaging system, for example, it's probably easier to ship qt as a wheel than to ship libc as a wheel.

Well, we can expect SOME base system! No system can exist without libc....

-CHB