fix(toolchains): correctly register musl/freethreaded toolchains for workspace

Author: rickeylev

CHANGELOG.md

@@ -84,6 +84,10 @@ END_UNRELEASED_TEMPLATE
   ([#3204](https://github.com/bazel-contrib/rules_python/issues/3204)).
 * (uv) {obj}`//python/uv:lock.bzl%lock` now works with a local platform
   runtime.
+* (toolchains) WORKSPACE builds now correctly register musl and freethreaded
+  variants. Setting {obj}`--py_linux_libc=musl` and `--py_freethreaded=yes` now
+  activate them, respectively.
+  ([#3262](https://github.com/bazel-contrib/rules_python/issues/3262)).
 
 {#v0-0-0-added}
 ### Added

python/private/toolchains_repo.bzl

@@ -214,7 +214,7 @@ def python_toolchain_build_file_content(
             user_repository_name = "{}_{}".format(user_repository_name, platform),
             python_version = python_version,
             set_python_version_constraint = set_python_version_constraint,
-            target_settings = [],
+            target_settings = meta.target_settings,
         ))
     return "\n\n".join(entries)
 

tests/toolchains/multi_platform_resolution/resolution_tests.bzl

@@ -141,13 +141,6 @@ def _test_toolchains(name):
         if runtime.libc:
             config_settings[labels.PY_LINUX_LIBC] = runtime.libc
 
-        # TODO: Workspace isn't correctly registering musl and freethreaded
-        # toolchains, so skip them for now.
-        target_compatible_with = []
-        if not BZLMOD_ENABLED and (runtime.libc == "musl" or
-                                   runtime.freethreaded == "yes"):
-            target_compatible_with = ["@platforms//:incompatible"]
-
         analysis_test(
             name = test_name,
             target = name + "_current_toolchain",