fix(core): return None from handle properties during Python shutdown

During interpreter finalization, `as_py()` calls `PyImport_ImportModule`
which fails because `sys.modules` is being cleared. Guard `make_py()`
with `py_is_finalizing()` to return None gracefully instead of raising.

Also consolidates the `py_is_finalizing()` helper into the shared header,
removing the duplicate definition from resource_handles.cpp.

Closes #1748

Made-with: Cursor

Author: Andy-Jost

cuda_core/cuda/core/_cpp/resource_handles.cpp

@@ -77,19 +77,7 @@ NvJitLinkDestroyFn p_nvJitLinkDestroy = nullptr;
 
 namespace {
 
-#if PY_VERSION_HEX < 0x030D0000
-extern "C" int _Py_IsFinalizing(void);
-#endif
-
-inline bool py_is_finalizing() noexcept {
-#if PY_VERSION_HEX >= 0x030D0000
-    return Py_IsFinalizing();
-#else
-    // Python < 3.13 does not expose Py_IsFinalizing() publicly. Use the private
-    // API that exists in those versions.
-    return _Py_IsFinalizing() != 0;
-#endif
-}
+using cuda_core::detail::py_is_finalizing;
 
 // Helper to release the GIL while calling into the CUDA driver.
 // This guard is *conditional*: if the caller already dropped the GIL,

cuda_core/cuda/core/_cpp/resource_handles.hpp

@@ -517,8 +517,24 @@ inline std::intptr_t as_intptr(const CuLinkHandle& h) noexcept {
 
 // as_py() - convert handle to Python wrapper object (returns new reference)
 namespace detail {
+
+#if PY_VERSION_HEX < 0x030D0000
+extern "C" int _Py_IsFinalizing(void);
+#endif
+
+inline bool py_is_finalizing() noexcept {
+#if PY_VERSION_HEX >= 0x030D0000
+    return Py_IsFinalizing();
+#else
+    return _Py_IsFinalizing() != 0;
+#endif
+}
+
 // n.b. class lookup is not cached to avoid deadlock hazard, see DESIGN.md
 inline PyObject* make_py(const char* module_name, const char* class_name, std::intptr_t value) noexcept {
+    if (py_is_finalizing()) {
+        Py_RETURN_NONE;
+    }
     PyObject* mod = PyImport_ImportModule(module_name);
     if (!mod) return nullptr;
     PyObject* cls = PyObject_GetAttrString(mod, class_name);