Add repo rule for fetching a Python SDK

[gurobokum]

Backbone for https://github.com/bazelbuild/bazel/issues/7467

• Doesn't support Windows
• I haven't covered it with tests due to the issue, shall I raise a ticket? What is the best approach to apply the tests for the implementation?
• Periodically I see Restarting after Install phase, what can be the cause?

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[Globegitter]

As much as I love seeing this, would it maybe make more sense to have this in an external repository? https://github.com/bazelbuild/rules_python/ has not received much love recently but imo it would probably be the best place for this to have fixes/updates to this repo rule independent of bazel releases. WDYT?

[gurobokum]

Hi @Globegitter
Yes, it sounds reasonable, I've created the PR here cause py toolchain is a part of bazel_toolsand the issue #7467 was created here. But looks like there is no anything that doesn't allow to move it out to python_rules

What do you think, @brandjon

Could you please also clarify my doubts above related testing
FYI as a part of testing approach I decided to create mocked python tar based on autoconf which simulates configuration/building and installing python and would like to upload it into the source code as done with six package. am I looking in a right direction or not?

[Globegitter]

Also quite interesting project that has a standalone python for windows: https://github.com/indygreg/python-build-standalone - though I have not tested it yet.

[gurobokum]

@Globegitter thank you for your sharing!
@brandjon, do you have any updates regarding it? Fill free to close the PR, cause the work should be done in https://github.com/bazelbuild/rules_python/
I would like to proceed work on the issue but needs your feedback

[keith]

We might want something like --enable-optimizations here too?

[jin]

Perhaps this should be reopened in rules_python?

[brandjon]

Right, this should definitely be reopened in rules_python. I'll transfer the underlying issue.

[jin]

Closing this for now - please reopen a new PR in the rules_python repository.

[ddlees]

FWIW I ran into this problem and saw it wasn't solved so I just recently published some rules that leverage pyenv to download, compile and register the python toolchain with whatever py_runtime_pair the project calls for.

It's probably a little rough but feedback and PRs are welcome; I just hope what's currently there can help some folks. 😉 🍻

https://github.com/digital-plumbers-union/rules_pyenv