Always need to specify --host_platform

[jberkel]

Hello, I'm new to bazel and am currently porting a project from cmake.
Unless I manually define a platform in my build file and pass it using --host_platform, the build always errors with:

No matching toolchains found for types @rules_foreign_cc//foreign_cc/private/framework:shell_toolchain.

I can get it to work with:

platform(
    name = "macos_arm64",
    constraint_values = [
        "@platforms//cpu:arm64",
        "@platforms//os:macos",
    ]
)


$ bazel build ... --host_platform=@myproject//:macos_arm64

When I check the value of the autodetected host, I get the following:

$ bazel query "@local_config_platform//:host" --output=build
# /private/var/tmp/_bazel_jberkel/71875215b69ba976a8ee3a9812122d50/external/local_config_platform/BUILD.bazel:4:9
platform(
  name = "host",
  constraint_values = ["@platforms~0.0.4//cpu:aarch64", "@platforms~0.0.4//os:osx"],
)

My understanding is that this should work without manually specifying --host_platform, as the autodetected values are identical to the ones I specify on the command line (aarch64 is just an alias for arm64).

This is with Bazel 6 and the latest rules_foreign_cc (9acbb35)

I found #212 but it seems to imply that the issue is already fixed.