PyPy support

[YannickJadoul]

Are we interested in building PyPy wheels with cibuildwheel, @joerick and @mayeut? I would be. Apparently, PyPy now also offers manylinux images with PyPy executables.

I'm happy to look into this, if agreed this would be a useful addition to cibuildwheel. It shouldn't even be a huge effort, I'd guess. But then should also maybe have a think about whether to make this an opt-in feature, and how?

[YannickJadoul]

Hmmm, only now noticed this is for the manylinux2010 standard, so this semi-depends on #135

[joerick]

Oooh, that looks great! Yes that feels like a logical step for cibuildwheel. I actually didn't realise Cpython extensions would work with Pypy, but it looks like they support that. I'd be happy to just add it to CIBW_BUILD by default, assuming the builds are painless enough :D

[altendky]

cpython c-api isn't the only thing to compile. there's cffi too.

[YannickJadoul]

Definitely! And even more advisable for PyPy, as far as I know.
But of course, since the C API is now +- complete in PyPy, the first step could already just easily allow developers to target PyPy with their existing code?

Either way, I think cibuildwheel is quite agnostic about the underlying mechanism, or am I forgetting something?

[altendky]

Oh yes, cffi vs c-api shouldn't really matter to cibuildwheel I don't think. I was just mentioning the other sort of project that needs binary wheels. Anyways, I would tend towards adding it to the defaults. I think encouraging more PyPy awareness and support is a good thing.

[altendky]

fyi, https://github.com/antocuni/pypy-wheels/tree/master/docker/image

[YannickJadoul]

@altendky Thanks!
Was I just hallucinating when I thought I'd seen a ready and published manylinux2010 image for PyPy, then, a few months ago?

Ah, no, wait. What's the difference with https://github.com/pypy/manylinux?