Also name the BUILD file in external repository roots BUILD.bazel

[person142]

PR Checklist

Please check if your PR fulfills the following requirements:

• Does not include precompiled binaries, eg. .par files. See CONTRIBUTING.md for info
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature (please, look at the "Scope of the project" section in the README.md file)
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

Closes #440

The build file in the repository roots generated by pip_repository is still BUILD and not BUILD.bazel. Since pip_parse has only one layer of directories, the external repository then ends up with a BUILD and a BUILD.bazel.

What is the new behavior?

It's now called BUILD.bazel, which means pip_parse later overwrites it with the final BUILD.bazel.

Does this PR introduce a breaking change?

• Yes
• No

Other information

This prevents a regression of #427 with pip_parse.

[person142]

This comment: #441 (comment) gives an example that fails on master but passes on this branch.

[hrfuller]

Can you move this line inside the else block here?

It shouldn't have been part of _construct_pypath in the first place, which was my mistake while refactoring. The root level BUILD.bazel file is only needed by pip_install. pip_parse already creates a root level BUILD.bazel in each repository via the extract_wheel function.

[person142]

Done in 6e92245.

The here link above links back to the comment, but I'm assuming you were referring to this else:

https://github.com/bazelbuild/rules_python/blob/master/python/pip_install/pip_repository.bzl#L82

I put it outside that conditional, since we do want the empty build file inside the repository where the requirements.bzl is generated-otherwise user code can't load from it. But it will be left out of the repositories for the individual packages still because it's not being injected here:

https://github.com/bazelbuild/rules_python/blob/master/python/pip_install/pip_repository.bzl#L215

[hrfuller]

Thank you! Yes you read my mind. I was mixing up with whl_library invocation for that else block.

[person142]

Thanks for reviewing @hrfuller.