Add test_standalone_enum_module.py, standalone_enum_module.cpp

Author: rwgk

tests/CMakeLists.txt

@@ -172,6 +172,7 @@ set(PYBIND11_TEST_FILES
     test_scoped_critical_section
     test_sequences_and_iterators
     test_smart_ptr
+    test_standalone_enum_module.py
     test_stl
     test_stl_binders
     test_tagbased_polymorphic
@@ -249,6 +250,7 @@ tests_extra_targets("test_exceptions.py" "cross_module_interleaved_error_already
 tests_extra_targets("test_gil_scoped.py" "cross_module_gil_utils")
 tests_extra_targets("test_cpp_conduit.py"
                     "exo_planet_pybind11;exo_planet_c_api;home_planet_very_lonely_traveler")
+tests_extra_targets("test_standalone_enum_module.py" "standalone_enum_module")
 
 set(PYBIND11_EIGEN_REPO
     "https://gitlab.com/libeigen/eigen.git"

tests/standalone_enum_module.cpp

@@ -0,0 +1,15 @@
+// Copyright (c) 2026 The pybind Community.
+
+#include <pybind11/pybind11.h>
+
+namespace standalone_enum_module_ns {
+enum class SomeEnum { value1, value2 };
+}
+
+using namespace standalone_enum_module_ns;
+
+PYBIND11_MODULE(standalone_enum_module, m) {
+    pybind11::enum_<SomeEnum>(m, "SomeEnum")
+        .value("value1", SomeEnum::value1)
+        .value("value2", SomeEnum::value2);
+}

tests/test_standalone_enum_module.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+import os
+
+import env
+
+
+def test_enum_import_exit_no_crash():
+    # Modeled after reproducer under issue #5976
+    env.check_script_success_in_subprocess(
+        f"""
+        import sys
+        sys.path.insert(0, {os.path.dirname(env.__file__)!r})
+        import standalone_enum_module as m
+        assert int(m.SomeEnum.value1) == 0
+        assert int(m.SomeEnum.value2) == 1
+        """,
+        rerun=1,
+    )