@rules_swift_package_manager//config_settings/spm/platform:macos matching in a linux docker container on mac os

[roya1v]

I'm trying to build a swift project in a linux docker container on mac os and I get an error that a module cannot be imported, because it's only available on apple platforms. This import should be hidden behind a flag that should be only passed on apple platforms. But it's still getting passed on Linux.
Here is the BUILD.bazel which doesn't work

swift_library(
    name = "SystemPackage.rspm",
    always_include_developer_search_paths = True,
    copts = [
        "-DSWIFT_PACKAGE",
        "-DSYSTEM_PACKAGE",
    ] + select({
        "@rules_swift_package_manager//config_settings/spm/configuration:debug": ["-DENABLE_MOCKING"],
        "@rules_swift_package_manager//config_settings/spm/platform:ios": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@rules_swift_package_manager//config_settings/spm/platform:macos": ["-DSYSTEM_PACKAGE_DARWIN"], # <- this
        "@rules_swift_package_manager//config_settings/spm/platform:tvos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@rules_swift_package_manager//config_settings/spm/platform:visionos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@rules_swift_package_manager//config_settings/spm/platform:watchos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "//conditions:default": [],
    }),
# ...

If I comment this line out or replace it for the platform condition behind this one, it works just fine:

swift_library(
    name = "SystemPackage.rspm",
    always_include_developer_search_paths = True,
    copts = [
        "-DSWIFT_PACKAGE",
        "-DSYSTEM_PACKAGE",
    ] + select({
        "@rules_swift_package_manager//config_settings/spm/configuration:debug": ["-DENABLE_MOCKING"],
        "@rules_swift_package_manager//config_settings/spm/platform:ios": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@platforms//os:macos": ["-DSYSTEM_PACKAGE_DARWIN"], # <- like this
        "@rules_swift_package_manager//config_settings/spm/platform:tvos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@rules_swift_package_manager//config_settings/spm/platform:visionos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "@rules_swift_package_manager//config_settings/spm/platform:watchos": ["-DSYSTEM_PACKAGE_DARWIN"],
        "//conditions:default": [],
    }),
    deps = ["@swiftpkg_swift_system//:CSystem.rspm"],

If it helps here is the code https://github.com/roya1v/generics-pizza/blob/main/BUILD.bazel#L10 (It uses a fork of this repo for a different fix, but I also tried it with the upstream version)