Add test to expose #265

GaudiConfiguration/tests/python/test_error_conditions.py

+#####################################################################################
+# (c) Copyright 2023 CERN for the benefit of the LHCb and ATLAS collaborations      #
+#                                                                                   #
+# This software is distributed under the terms of the Apache version 2 licence,     #
+# copied verbatim in the file "LICENSE".                                            #
+#                                                                                   #
+# In applying this licence, CERN does not waive the privileges and immunities       #
+# granted to it by virtue of its status as an Intergovernmental Organization        #
+# or submit itself to any jurisdiction.                                             #
+#####################################################################################
+import pytest
+
+
+def test_1():
+    from GaudiConfig2.Configurables.TestConf import AlgWithVectors
+
+    alg = AlgWithVectors()
+    with pytest.raises(TypeError, match=r"cannot set property VS .*"):
+        alg.VS = [3]