Run Python bazel stuff without requiring full xcode on macOS

[virtuald]

My preferred development system is a mac, and I can currently do development on RobotPy without needing more than the xcode command line tools. It seems that running allwpilib's build requires the full xcode install. Can we document a way to avoid/disable this?

... it seems like I'm always running out of disk space since my mac only has 500GB of space. I'd rather not spend the extra 12GB+ on xcode if I don't have to.

[auscompgeek]

The only thing I can imagine would require full Xcode is https://github.com/bazelbuild/apple_support but that claims to support the Xcode CLT. Not entirely sure what's happening there.

[KangarooKoala]

I've also been running into issues (encountering errors like Dotted version components must all start with the form \d+([a-z0-9]*?)?(\d+)? but got 'None'). While looking into those particular errors, I found this in a July 25 2024 comment:

you have to have a full version of Xcode installed, [the unclear error message] seems like some poor error handling somewhere

In addition, the the note in the apple_support README was added September 23 this year, so it might be possible that it still isn't fully working yet.

[auscompgeek]

bazelbuild/bazel#23111 (comment) mentions an env var BAZEL_NO_APPLE_CPP_TOOLCHAIN=1. So if someone without Xcode installed could try bazel build --repo_env=BAZEL_NO_APPLE_CPP_TOOLCHAIN=1 //..., then we can add it to the .bazelrc.

common --repo_env=BAZEL_NO_APPLE_CPP_TOOLCHAIN=1

[virtuald]

That does not work.