Description of the problem / feature request:

Repository rules already have access to repository_os which allows rules to change their behaviour based on the exec OS. Repository rules should also know the exec architecture. Repository rules currently work around this limitation by uname -m, which isn't ideal. See rules_go.

Feature requests: what underlying problem are you trying to solve with this feature?

Repository rules create potentially brittle and strange workarounds to get the exec CPU. There is no standardisation and no official guidance on how best to create repository rules which target multiple platforms.

What operating system are you running Bazel on?

Linux x86_64

What's the output of bazel info release?

❯ bazel info release
Starting local Bazel server and connecting to it...
release 5.0.0

Have you found anything relevant by searching the web?

Replace this line with your answer.

• Failed to using select() in WORKSPACE #11655 (comment)
• Feature request: add target platform info in repository_ctx  #4636 (request was target, not exec)

Any other information, logs, or outputs that you want to share?

N/A