Preserve CUDA 12 registered handle getter errors

Carry forward #2551 and its regression test. A KeyError inside a registered getter must propagate instead of being reported as an unknown handle type.

Signed-off-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>

Author: rwgk

cuda_bindings_12/cuda/bindings/utils/__init__.py

@@ -26,6 +26,9 @@ def get_cuda_native_handle(obj: Any) -> int:
     """
     obj_type = type(obj)
     try:
-        return _handle_getters[obj_type](obj)
+        getter = _handle_getters[obj_type]
     except KeyError:
         raise TypeError("Unknown type: " + str(obj_type)) from None
+    # Deliberately outside the try: a KeyError raised by the getter itself is a
+    # bug in that getter, not an unregistered type.
+    return getter(obj)

cuda_bindings_12/tests/test_utils.py

@@ -92,6 +92,27 @@ def test_get_handle_error(target):
         handle = get_cuda_native_handle(target)
 
 
+@pytest.mark.agent_authored(model="claude-opus-5")
+def test_get_handle_does_not_report_a_registered_type_as_unknown(monkeypatch):
+    """A KeyError from inside a handle getter is a bug in that getter.
+
+    Reporting it as "Unknown type" is wrong twice over: the type *is*
+    registered, and `from None` hides the traceback that would say otherwise.
+    """
+    from cuda.bindings.utils import _handle_getters
+
+    class Registered:
+        pass
+
+    def getter(_obj):
+        raise KeyError("lookup inside the getter failed")
+
+    monkeypatch.setitem(_handle_getters, Registered, getter)
+
+    with pytest.raises(KeyError, match="lookup inside the getter failed"):
+        get_cuda_native_handle(Registered())
+
+
 @pytest.mark.parametrize(
     "module",
     [