fixed failing tests

lib/iris/tests/unit/data_manager/test_DataManager.py

@@ -4,8 +4,6 @@
 # See LICENSE in the root of the repository for full licensing details.
 """Unit tests for the :class:`iris._data_manager.DataManager`."""
 
-import iris.exceptions
-
 # Import iris.tests first so that some things can be initialised before
 # importing anything else.
 import iris.tests as tests  # isort:skip
@@ -170,13 +168,13 @@ def setUp(self):
     def test_array_none(self):
         self.dm._real_array = None
         emsg = "Unexpected data state, got no lazy or real data, and no shape."
-        with self.assertRaisesRegex(iris.exceptions.InvalidCubeError, emsg):
+        with self.assertRaisesRegex(ValueError, emsg):
             self.dm._assert_axioms()
 
     def test_array_all(self):
         self.dm._lazy_array = self.lazy_array
         emsg = "Unexpected data state, got both lazy and real data."
-        with self.assertRaisesRegex(iris.exceptions.InvalidCubeError, emsg):
+        with self.assertRaisesRegex(ValueError, emsg):
             self.dm._assert_axioms()