From 5f580c9e3d5084a50a010b80c94f06bf74acf31d Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Tue, 20 May 2025 22:05:28 +0200
Subject: [PATCH 1/8] Use the `launcher_maker` toolchain if available

---
 MODULE.bazel                                  |  2 +-
 internal_dev_deps.bzl                         |  6 ++---
 python/private/py_executable.bzl              | 23 +++++++++++-----
 python/private/py_repositories.bzl            |  6 +++++
 tests/base_rules/py_executable_base_tests.bzl | 26 +++++++++++++++++++
 tests/support/platforms/BUILD.bazel           |  8 ++++++
 tests/support/platforms/platforms.bzl         |  4 +++
 7 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/MODULE.bazel b/MODULE.bazel
index 6e9b725c53..7933fbf6d0 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -4,7 +4,7 @@ module(
     compatibility_level = 1,
 )
 
-bazel_dep(name = "bazel_features", version = "1.21.0")
+bazel_dep(name = "bazel_features", version = "1.30.0")
 bazel_dep(name = "bazel_skylib", version = "1.8.2")
 bazel_dep(name = "rules_cc", version = "0.1.5")
 bazel_dep(name = "platforms", version = "0.0.11")
diff --git a/internal_dev_deps.bzl b/internal_dev_deps.bzl
index 811240a06a..e357e204a0 100644
--- a/internal_dev_deps.bzl
+++ b/internal_dev_deps.bzl
@@ -231,9 +231,9 @@ def rules_python_internal_deps():
 
     http_archive(
         name = "bazel_features",
-        sha256 = "d7787da289a7fb497352211ad200ec9f698822a9e0757a4976fd9f713ff372b3",
-        strip_prefix = "bazel_features-1.9.1",
-        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.9.1/bazel_features-v1.9.1.tar.gz",
+        sha256 = "a660027f5a87f13224ab54b8dc6e191693c554f2692fcca46e8e29ee7dabc43b",
+        strip_prefix = "bazel_features-1.30.0",
+        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.30.0/bazel_features-v1.30.0.tar.gz",
     )
 
     http_archive(
diff --git a/python/private/py_executable.bzl b/python/private/py_executable.bzl
index 669951e172..a0394e1603 100644
--- a/python/private/py_executable.bzl
+++ b/python/private/py_executable.bzl
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Common functionality between test/binary executables."""
 
+load("@bazel_features//:features.bzl", "bazel_features")
 load("@bazel_skylib//lib:dicts.bzl", "dicts")
 load("@bazel_skylib//lib:paths.bzl", "paths")
 load("@bazel_skylib//lib:structs.bzl", "structs")
@@ -69,6 +70,7 @@ load(":venv_runfiles.bzl", "create_venv_app_files")
 _py_builtins = py_internal
 _EXTERNAL_PATH_PREFIX = "external"
 _ZIP_RUNFILES_DIRECTORY_NAME = "runfiles"
+_LAUNCHER_MAKER_TOOLCHAIN_TYPE = "@bazel_tools//tools/launcher:launcher_maker_toolchain_type"
 
 # Non-Google-specific attributes for executables
 # These attributes are for rules that accept Python sources.
@@ -228,17 +230,19 @@ accepting arbitrary Python versions.
                 "@platforms//os:windows",
             ],
         ),
-        "_windows_launcher_maker": lambda: attrb.Label(
-            default = "@bazel_tools//tools/launcher:launcher_maker",
-            cfg = "exec",
-            executable = True,
-        ),
         "_zipper": lambda: attrb.Label(
             cfg = "exec",
             executable = True,
             default = "@bazel_tools//tools/zip:zipper",
         ),
     },
+    {
+        "_windows_launcher_maker": lambda: attrb.Label(
+            default = "@bazel_tools//tools/launcher:launcher_maker",
+            cfg = "exec",
+            executable = True,
+        ),
+    } if not bazel_features.rules._has_launcher_maker_toolchain else {},
 )
 
 def convert_legacy_create_init_to_int(kwargs):
@@ -777,6 +781,11 @@ def _create_stage1_bootstrap(
         is_executable = True,
     )
 
+def _find_launcher_maker(ctx):
+    if bazel_features.rules._has_launcher_maker_toolchain:
+        return ctx.toolchains[_LAUNCHER_MAKER_TOOLCHAIN_TYPE].binary
+    return ctx.executable._windows_launcher_maker
+
 def _create_windows_exe_launcher(
         ctx,
         *,
@@ -797,7 +806,7 @@ def _create_windows_exe_launcher(
 
     launcher = ctx.attr._launcher[DefaultInfo].files_to_run.executable
     ctx.actions.run(
-        executable = ctx.executable._windows_launcher_maker,
+        executable = _find_launcher_maker(ctx),
         arguments = [launcher.path, launch_info, output.path],
         inputs = [launcher],
         outputs = [output],
@@ -1838,7 +1847,7 @@ def create_executable_rule_builder(implementation, **kwargs):
             ruleb.ToolchainType(TOOLCHAIN_TYPE),
             ruleb.ToolchainType(EXEC_TOOLS_TOOLCHAIN_TYPE, mandatory = False),
             ruleb.ToolchainType("@bazel_tools//tools/cpp:toolchain_type", mandatory = False),
-        ],
+        ] + ([ruleb.ToolchainType(_LAUNCHER_MAKER_TOOLCHAIN_TYPE)] if bazel_features.rules._has_launcher_maker_toolchain else []),
         cfg = dict(
             implementation = _transition_executable_impl,
             inputs = TRANSITION_LABELS + [labels.PYTHON_VERSION],
diff --git a/python/private/py_repositories.bzl b/python/private/py_repositories.bzl
index e3ab11c561..7817137c9e 100644
--- a/python/private/py_repositories.bzl
+++ b/python/private/py_repositories.bzl
@@ -72,6 +72,12 @@ def py_repositories(transition_settings = []):
         strip_prefix = "rules_cc-0.1.5",
         urls = ["https://github.com/bazelbuild/rules_cc/releases/download/0.1.5/rules_cc-0.1.5.tar.gz"],
     )
+    http_archive(
+        name = "bazel_features",
+        sha256 = "a660027f5a87f13224ab54b8dc6e191693c554f2692fcca46e8e29ee7dabc43b",
+        strip_prefix = "bazel_features-1.30.0",
+        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.30.0/bazel_features-v1.30.0.tar.gz",
+    )
 
     # Needed by rules_cc, triggered by @rules_java_prebuilt in Bazel by using @rules_cc//cc:defs.bzl
     # NOTE: This name must be com_google_protobuf until Bazel drops WORKSPACE
diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index e41bc2c022..87a2683c6c 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Tests common to py_binary and py_test (executable rules)."""
 
+load("@bazel_features//:features.bzl", "bazel_features")
 load("@rules_python//python:py_runtime_info.bzl", RulesPythonPyRuntimeInfo = "PyRuntimeInfo")
 load("@rules_testing//lib:analysis_test.bzl", "analysis_test")
 load("@rules_testing//lib:truth.bzl", "matching")
@@ -114,6 +115,31 @@ def _test_basic_zip_impl(env, target):
 
 _tests.append(_test_basic_zip)
 
+def _test_cross_compile_to_unix(name, config):
+    if not bazel_features.rules._has_launcher_maker_toolchain or "py_test" in str(config.rule):
+        # The default test toolchain prevents cross-compiling py_test to
+        # a non-exec platform.
+        return
+    rt_util.helper_target(
+        config.rule,
+        name = name + "_subject",
+        main_module = "dummy",
+    )
+    analysis_test(
+        name = name,
+        impl = _test_cross_compile_to_unix_impl,
+        target = name + "_subject",
+        config_settings = {
+            "//command_line_option:platforms": [platform_targets.EXOTIC_UNIX],
+        },
+        expect_failure = True,
+    )
+
+def _test_cross_compile_to_unix_impl(_env, _target):
+    pass
+
+_tests.append(_test_cross_compile_to_unix)
+
 def _test_executable_in_runfiles(name, config):
     rt_util.helper_target(
         config.rule,
diff --git a/tests/support/platforms/BUILD.bazel b/tests/support/platforms/BUILD.bazel
index 41d7936394..eeb7ccb597 100644
--- a/tests/support/platforms/BUILD.bazel
+++ b/tests/support/platforms/BUILD.bazel
@@ -75,3 +75,11 @@ platform(
         "@platforms//cpu:aarch64",
     ],
 )
+
+platform(
+    name = "exotic_unix",
+    constraint_values = [
+        "@platforms//os:linux",
+        "@platforms//cpu:s390x",
+    ],
+)
diff --git a/tests/support/platforms/platforms.bzl b/tests/support/platforms/platforms.bzl
index af049f202c..92a1d61844 100644
--- a/tests/support/platforms/platforms.bzl
+++ b/tests/support/platforms/platforms.bzl
@@ -10,4 +10,8 @@ platform_targets = struct(
     WINDOWS = Label("//tests/support/platforms:windows"),
     WINDOWS_AARCH64 = Label("//tests/support/platforms:windows_aarch64"),
     WINDOWS_X86_64 = Label("//tests/support/platforms:windows_x86_64"),
+
+    # Unspecified Unix platform that is unlikely to be the host platform in CI,
+    # but still provides a Python toolchain.
+    EXOTIC_UNIX = Label("//tests/support/platforms:exotic_unix"),
 )

From 93dff6a6fd2bfc342708547c4bfdf17306a4256c Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 10:36:32 +0100
Subject: [PATCH 2/8] Switch to rp_config

---
 MODULE.bazel                                  | 2 +-
 internal_dev_deps.bzl                         | 6 +++---
 python/private/internal_config_repo.bzl       | 4 ++++
 python/private/py_executable.bzl              | 8 ++++----
 python/private/py_repositories.bzl            | 6 ------
 tests/base_rules/py_executable_base_tests.bzl | 4 ++--
 6 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/MODULE.bazel b/MODULE.bazel
index 7933fbf6d0..6e9b725c53 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -4,7 +4,7 @@ module(
     compatibility_level = 1,
 )
 
-bazel_dep(name = "bazel_features", version = "1.30.0")
+bazel_dep(name = "bazel_features", version = "1.21.0")
 bazel_dep(name = "bazel_skylib", version = "1.8.2")
 bazel_dep(name = "rules_cc", version = "0.1.5")
 bazel_dep(name = "platforms", version = "0.0.11")
diff --git a/internal_dev_deps.bzl b/internal_dev_deps.bzl
index e357e204a0..811240a06a 100644
--- a/internal_dev_deps.bzl
+++ b/internal_dev_deps.bzl
@@ -231,9 +231,9 @@ def rules_python_internal_deps():
 
     http_archive(
         name = "bazel_features",
-        sha256 = "a660027f5a87f13224ab54b8dc6e191693c554f2692fcca46e8e29ee7dabc43b",
-        strip_prefix = "bazel_features-1.30.0",
-        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.30.0/bazel_features-v1.30.0.tar.gz",
+        sha256 = "d7787da289a7fb497352211ad200ec9f698822a9e0757a4976fd9f713ff372b3",
+        strip_prefix = "bazel_features-1.9.1",
+        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.9.1/bazel_features-v1.9.1.tar.gz",
     )
 
     http_archive(
diff --git a/python/private/internal_config_repo.bzl b/python/private/internal_config_repo.bzl
index d5192ec44b..1e18e9e230 100644
--- a/python/private/internal_config_repo.bzl
+++ b/python/private/internal_config_repo.bzl
@@ -32,6 +32,7 @@ config = struct(
   enable_pystar = True,
   enable_pipstar = {enable_pipstar},
   enable_deprecation_warnings = {enable_deprecation_warnings},
+  bazel_9_or_later = {bazel_9_or_later},
   BuiltinPyInfo = getattr(getattr(native, "legacy_globals", None), "PyInfo", {builtin_py_info_symbol}),
   BuiltinPyRuntimeInfo = getattr(getattr(native, "legacy_globals", None), "PyRuntimeInfo", {builtin_py_runtime_info_symbol}),
   BuiltinPyCcLinkParamsProvider = getattr(getattr(native, "legacy_globals", None), "PyCcLinkParamsProvider", {builtin_py_cc_link_params_provider}),
@@ -91,10 +92,12 @@ def _internal_config_repo_impl(rctx):
         builtin_py_info_symbol = "None"
         builtin_py_runtime_info_symbol = "None"
         builtin_py_cc_link_params_provider = "None"
+        bazel_9_or_later = "True"
     else:
         builtin_py_info_symbol = "PyInfo"
         builtin_py_runtime_info_symbol = "PyRuntimeInfo"
         builtin_py_cc_link_params_provider = "PyCcLinkParamsProvider"
+        bazel_9_or_later = "False"
 
     rctx.file("rules_python_config.bzl", _CONFIG_TEMPLATE.format(
         build_python_zip_default = repo_utils.get_platforms_os_name(rctx) == "windows",
@@ -103,6 +106,7 @@ def _internal_config_repo_impl(rctx):
         builtin_py_info_symbol = builtin_py_info_symbol,
         builtin_py_runtime_info_symbol = builtin_py_runtime_info_symbol,
         builtin_py_cc_link_params_provider = builtin_py_cc_link_params_provider,
+        bazel_9_or_later = bazel_9_or_later,
     ))
 
     shim_content = _PY_INTERNAL_SHIM
diff --git a/python/private/py_executable.bzl b/python/private/py_executable.bzl
index a0394e1603..ca05e3a206 100644
--- a/python/private/py_executable.bzl
+++ b/python/private/py_executable.bzl
@@ -13,12 +13,12 @@
 # limitations under the License.
 """Common functionality between test/binary executables."""
 
-load("@bazel_features//:features.bzl", "bazel_features")
 load("@bazel_skylib//lib:dicts.bzl", "dicts")
 load("@bazel_skylib//lib:paths.bzl", "paths")
 load("@bazel_skylib//lib:structs.bzl", "structs")
 load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
+load("@rules_python_internal//:rules_python_config.bzl", rp_config = "config")
 load(":attr_builders.bzl", "attrb")
 load(
     ":attributes.bzl",
@@ -242,7 +242,7 @@ accepting arbitrary Python versions.
             cfg = "exec",
             executable = True,
         ),
-    } if not bazel_features.rules._has_launcher_maker_toolchain else {},
+    } if not rp_config.bazel_9_or_later else {},
 )
 
 def convert_legacy_create_init_to_int(kwargs):
@@ -782,7 +782,7 @@ def _create_stage1_bootstrap(
     )
 
 def _find_launcher_maker(ctx):
-    if bazel_features.rules._has_launcher_maker_toolchain:
+    if rp_config.bazel_9_or_later:
         return ctx.toolchains[_LAUNCHER_MAKER_TOOLCHAIN_TYPE].binary
     return ctx.executable._windows_launcher_maker
 
@@ -1847,7 +1847,7 @@ def create_executable_rule_builder(implementation, **kwargs):
             ruleb.ToolchainType(TOOLCHAIN_TYPE),
             ruleb.ToolchainType(EXEC_TOOLS_TOOLCHAIN_TYPE, mandatory = False),
             ruleb.ToolchainType("@bazel_tools//tools/cpp:toolchain_type", mandatory = False),
-        ] + ([ruleb.ToolchainType(_LAUNCHER_MAKER_TOOLCHAIN_TYPE)] if bazel_features.rules._has_launcher_maker_toolchain else []),
+        ] + ([ruleb.ToolchainType(_LAUNCHER_MAKER_TOOLCHAIN_TYPE)] if rp_config.bazel_9_or_later else []),
         cfg = dict(
             implementation = _transition_executable_impl,
             inputs = TRANSITION_LABELS + [labels.PYTHON_VERSION],
diff --git a/python/private/py_repositories.bzl b/python/private/py_repositories.bzl
index 7817137c9e..e3ab11c561 100644
--- a/python/private/py_repositories.bzl
+++ b/python/private/py_repositories.bzl
@@ -72,12 +72,6 @@ def py_repositories(transition_settings = []):
         strip_prefix = "rules_cc-0.1.5",
         urls = ["https://github.com/bazelbuild/rules_cc/releases/download/0.1.5/rules_cc-0.1.5.tar.gz"],
     )
-    http_archive(
-        name = "bazel_features",
-        sha256 = "a660027f5a87f13224ab54b8dc6e191693c554f2692fcca46e8e29ee7dabc43b",
-        strip_prefix = "bazel_features-1.30.0",
-        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v1.30.0/bazel_features-v1.30.0.tar.gz",
-    )
 
     # Needed by rules_cc, triggered by @rules_java_prebuilt in Bazel by using @rules_cc//cc:defs.bzl
     # NOTE: This name must be com_google_protobuf until Bazel drops WORKSPACE
diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index 87a2683c6c..3020fb3de8 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -13,8 +13,8 @@
 # limitations under the License.
 """Tests common to py_binary and py_test (executable rules)."""
 
-load("@bazel_features//:features.bzl", "bazel_features")
 load("@rules_python//python:py_runtime_info.bzl", RulesPythonPyRuntimeInfo = "PyRuntimeInfo")
+load("@rules_python_internal//:rules_python_config.bzl", rp_config = "config")
 load("@rules_testing//lib:analysis_test.bzl", "analysis_test")
 load("@rules_testing//lib:truth.bzl", "matching")
 load("@rules_testing//lib:util.bzl", rt_util = "util")
@@ -116,7 +116,7 @@ def _test_basic_zip_impl(env, target):
 _tests.append(_test_basic_zip)
 
 def _test_cross_compile_to_unix(name, config):
-    if not bazel_features.rules._has_launcher_maker_toolchain or "py_test" in str(config.rule):
+    if not rp_config.bazel_9_or_later or "py_test" in str(config.rule):
         # The default test toolchain prevents cross-compiling py_test to
         # a non-exec platform.
         return

From 69e7340f75351675a885386de840fa6494baf088 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 16:08:41 +0100
Subject: [PATCH 3/8] Apply suggestions from code review

---
 tests/base_rules/py_executable_base_tests.bzl | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index 3020fb3de8..c5de44f98d 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -138,7 +138,10 @@ def _test_cross_compile_to_unix(name, config):
 def _test_cross_compile_to_unix_impl(_env, _target):
     pass
 
-_tests.append(_test_cross_compile_to_unix)
+# The default test toolchain prevents cross-compiling py_test to a non-exec
+# platform. 
+if rp_config.bazel_9_or_later and "py_test" not in str(config.rule):
+    _tests.append(_test_cross_compile_to_unix)
 
 def _test_executable_in_runfiles(name, config):
     rt_util.helper_target(

From 515f5f421bef5c818bd5ef53a7e244977e3d0d10 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 16:08:52 +0100
Subject: [PATCH 4/8] Apply suggestion from @fmeum

---
 tests/base_rules/py_executable_base_tests.bzl | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index c5de44f98d..4adb2da9bb 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -116,10 +116,6 @@ def _test_basic_zip_impl(env, target):
 _tests.append(_test_basic_zip)
 
 def _test_cross_compile_to_unix(name, config):
-    if not rp_config.bazel_9_or_later or "py_test" in str(config.rule):
-        # The default test toolchain prevents cross-compiling py_test to
-        # a non-exec platform.
-        return
     rt_util.helper_target(
         config.rule,
         name = name + "_subject",

From e66ef701342004b9ab1b0b0dde1143087b8bac3b Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 16:10:31 +0100
Subject: [PATCH 5/8] Update py_executable_base_tests.bzl

---
 tests/base_rules/py_executable_base_tests.bzl | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index 4adb2da9bb..9b2927f032 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -134,9 +134,7 @@ def _test_cross_compile_to_unix(name, config):
 def _test_cross_compile_to_unix_impl(_env, _target):
     pass
 
-# The default test toolchain prevents cross-compiling py_test to a non-exec
-# platform. 
-if rp_config.bazel_9_or_later and "py_test" not in str(config.rule):
+if rp_config.bazel_9_or_later:
     _tests.append(_test_cross_compile_to_unix)
 
 def _test_executable_in_runfiles(name, config):

From ae2dd35bddbe63aedd9cc42c71c700681f4446b3 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 17:22:07 +0100
Subject: [PATCH 6/8] Update py_executable_base_tests.bzl

---
 tests/base_rules/py_executable_base_tests.bzl | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index 9b2927f032..6092ef4752 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -134,8 +134,7 @@ def _test_cross_compile_to_unix(name, config):
 def _test_cross_compile_to_unix_impl(_env, _target):
     pass
 
-if rp_config.bazel_9_or_later:
-    _tests.append(_test_cross_compile_to_unix)
+_tests.append(_test_cross_compile_to_unix) if rp_config.bazel_9_or_later else None
 
 def _test_executable_in_runfiles(name, config):
     rt_util.helper_target(

From cc2fa384784060d3651215d4014b47b6733f73b8 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 19:50:14 +0100
Subject: [PATCH 7/8] Update py_executable.bzl

---
 python/private/py_executable.bzl              | 8 +++++---
 tests/base_rules/py_executable_base_tests.bzl | 6 ++++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/python/private/py_executable.bzl b/python/private/py_executable.bzl
index ca05e3a206..99a3dffb49 100644
--- a/python/private/py_executable.bzl
+++ b/python/private/py_executable.bzl
@@ -783,8 +783,8 @@ def _create_stage1_bootstrap(
 
 def _find_launcher_maker(ctx):
     if rp_config.bazel_9_or_later:
-        return ctx.toolchains[_LAUNCHER_MAKER_TOOLCHAIN_TYPE].binary
-    return ctx.executable._windows_launcher_maker
+        return (ctx.toolchains[_LAUNCHER_MAKER_TOOLCHAIN_TYPE].binary, _LAUNCHER_MAKER_TOOLCHAIN_TYPE)
+    return (ctx.executable._windows_launcher_maker, None)
 
 def _create_windows_exe_launcher(
         ctx,
@@ -805,8 +805,9 @@ def _create_windows_exe_launcher(
     launch_info.add("1" if use_zip_file else "0", format = "use_zip_file=%s")
 
     launcher = ctx.attr._launcher[DefaultInfo].files_to_run.executable
+    executable, toolchain = _find_launcher_maker(ctx)
     ctx.actions.run(
-        executable = _find_launcher_maker(ctx),
+        executable = executable,
         arguments = [launcher.path, launch_info, output.path],
         inputs = [launcher],
         outputs = [output],
@@ -814,6 +815,7 @@ def _create_windows_exe_launcher(
         progress_message = "Creating launcher for %{label}",
         # Needed to inherit PATH when using non-MSVC compilers like MinGW
         use_default_shell_env = True,
+        toolchain = toolchain,
     )
 
 def _create_zip_file(ctx, *, output, zip_main, runfiles):
diff --git a/tests/base_rules/py_executable_base_tests.bzl b/tests/base_rules/py_executable_base_tests.bzl
index 6092ef4752..ed1a55021d 100644
--- a/tests/base_rules/py_executable_base_tests.bzl
+++ b/tests/base_rules/py_executable_base_tests.bzl
@@ -125,16 +125,18 @@ def _test_cross_compile_to_unix(name, config):
         name = name,
         impl = _test_cross_compile_to_unix_impl,
         target = name + "_subject",
+        # Cross-compilation of py_test fails since the default test toolchain
+        # requires an execution platform that matches the target platform.
         config_settings = {
             "//command_line_option:platforms": [platform_targets.EXOTIC_UNIX],
-        },
+        } if rp_config.bazel_9_or_later and not "py_test" in str(config.rule) else {},
         expect_failure = True,
     )
 
 def _test_cross_compile_to_unix_impl(_env, _target):
     pass
 
-_tests.append(_test_cross_compile_to_unix) if rp_config.bazel_9_or_later else None
+_tests.append(_test_cross_compile_to_unix)
 
 def _test_executable_in_runfiles(name, config):
     rt_util.helper_target(

From 0353e77bbcb5fcef0309eb0c0ae927d654f97a47 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Fri, 21 Nov 2025 20:43:59 +0100
Subject: [PATCH 8/8] Fix Bazel 8

---
 python/private/internal_config_repo.bzl | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/python/private/internal_config_repo.bzl b/python/private/internal_config_repo.bzl
index 1e18e9e230..b208037c13 100644
--- a/python/private/internal_config_repo.bzl
+++ b/python/private/internal_config_repo.bzl
@@ -88,16 +88,17 @@ _TRANSITION_SETTINGS_DEBUG_TEMPLATE = """
 """
 
 def _internal_config_repo_impl(rctx):
-    if not native.bazel_version or int(native.bazel_version.split(".")[0]) >= 8:
+    # An empty version signifies a development build, which is treated as
+    # the latest version.
+    bazel_major_version = int(native.bazel_version.split(".")[0]) if native.bazel_version else 99999
+    if bazel_major_version >= 8:
         builtin_py_info_symbol = "None"
         builtin_py_runtime_info_symbol = "None"
         builtin_py_cc_link_params_provider = "None"
-        bazel_9_or_later = "True"
     else:
         builtin_py_info_symbol = "PyInfo"
         builtin_py_runtime_info_symbol = "PyRuntimeInfo"
         builtin_py_cc_link_params_provider = "PyCcLinkParamsProvider"
-        bazel_9_or_later = "False"
 
     rctx.file("rules_python_config.bzl", _CONFIG_TEMPLATE.format(
         build_python_zip_default = repo_utils.get_platforms_os_name(rctx) == "windows",
@@ -106,7 +107,7 @@ def _internal_config_repo_impl(rctx):
         builtin_py_info_symbol = builtin_py_info_symbol,
         builtin_py_runtime_info_symbol = builtin_py_runtime_info_symbol,
         builtin_py_cc_link_params_provider = builtin_py_cc_link_params_provider,
-        bazel_9_or_later = bazel_9_or_later,
+        bazel_9_or_later = str(bazel_major_version >= 9),
     ))
 
     shim_content = _PY_INTERNAL_SHIM