Should @local_config_platform//:host be marked no-remote-exec (or maybe even no-remote)?

[EdSchouten]

Description of the feature request:

As of #22363, we have testing coverage in place for ensuring platforms as a whole can be marked no-remote-exec. This raises the question: should the default host platform be marked as such?

Think of it like this: the default host platform does not have any remote execution platform properties set up. This means that if such a platform were to be used for remote execution, it would likely just result in an error indicating that no workers exist having the empty set of platform properties. By marking it as no-remote-exec, we're essentially forcing the user to declare its own platform that has the right properties set.

Maybe we should even consider marking it no-remote. If a remote cache is shared between users running different operating systems, it isn't safe to upload actions that don't have platform properties set. But maybe that complicates the onboarding experience.

Which category does this issue belong to?

No response

What underlying problem are you trying to solve with this feature?

I've got a simple remote execution cluster that only has Linux workers, which I want to use from my Mac to speed up builds where possible. However, there are some actions that only run on macOS, which I want to run locally. So I declare two platforms:

platform(
    name = "remote_linux",
    constraint_values = [
        "@platforms//cpu:x86_64",
        "@platforms//os:linux",
    ],
    exec_properties = { ... },
)

platform(
    name = "local_fallback",
    exec_properties = {"no-remote-exec": "true"},
    parents = ["@local_config_platform//:host"],
)

And then call Bazel with --extra_execution_platforms=//:remote_linux,//:local_fallback. If @local_config_platform//:host itself were marked no-remote-exec, I could get rid of that second platform declaration.

Which operating system are you running Bazel on?

macOS

What is the output of bazel info release?

7.x

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

No response

Have you found anything relevant by searching the web?

No response

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

No response