Support Python 3.8 builds

[charris]

It would be nice to be able to build wheels for the upcoming 3.8 release candidates. If that is too much trouble, this is a request that 3.8 be supported as soon as possible after release.

[matthew-brett]

Easy enough for macOS, but I don't there's a Python 3.8 on the current Manylinux container ... pypa/manylinux#344

[mattip]

pypa/manylinux#344 was resolved, manylinux now supports 3.8.0rc1

[mattip]

is there something I can do to make multibuild support 3.8.0rc1? "grepping" the codebase showed only macos usage and some tests, I must have missed the linux python specification somewhere

[charris]

@mattip What is the question? Should work by editing numpy-wheels/.travis.yml and adding a build. The new manylinux1 64 bit docker image looks to have been built and available. The i386 version has not been updated.

[charris]

I think it is failing to install python3.8, probably because pre-releases have a different address: https://www.python.org/downloads/release/python-380rc1/

or https://www.python.org/ftp/python/3.8.0/Python-3.8.0rc1.tgz

[mattip]

xref MacPython/numpy-wheels#62 which fails. I think the problem is in manylinux_utils.sh, in the cpython_path function. Does the 3.8.0rc0 cpython actually live at /opt/python/cp* in the docker image?

[matthew-brett]

It isn't there no:

[root@f67b52320832 /]# ls /opt/python/
cp27-cp27m  cp27-cp27mu  cp34-cp34m  cp35-cp35m  cp36-cp36m  cp37-cp37m

Should it be?

[mattip]

pulling the latest manylinux2010_x86_64 with image id 26fcb1b78c2c, I do see it

[root@cea4fcd1d385 /]# ls /opt/python
cp27-cp27m  cp27-cp27mu  cp34-cp34m  cp35-cp35m  cp36-cp36m  \
cp37-cp37m  cp38-cp38

but not in the manylinux1_x86_64. I guess I need to repeat pypa/manylinux#344 against the manylinux1 branch. We could also try the manylinux2010 image in numpy-wheels, it should still be possible to tell it to create manylinux1-compatible wheels.

[mattip]

xref pypa/manylinux#360

[mattip]

the m was removed fromget_abi_tag in wheel.pep425tags.py by pypa/wheel#303 for python3.8 and up, so cpython_path in manylinux_utils.sh should check for 3.8 and adjust appropriately.

[matthew-brett]

Sorry Matti - you hit me at the beginning of the university term - things are a bit crazy here. Any interest in a PR for the RC for Mac?

[mattip]

Windows is hard, since Appveyor does not support it yet as far as I can tell.

[matthew-brett]

In the past, Appveyor has lagged behind the final Python release schedule by a few weeks, so we probably have to do the install ourselves for a while, even when the final version comes out.

See the install_python.ps1 script for the mechanism we used before - at the moment, it only supports versions without suffixes like rc1, but it could be extended. See MacPython/numpy-wheels@c513b92 for an example of use.