Skip mypy test on platforms using importlib_resources

sros2/test/test_mypy.py

@@ -19,4 +19,13 @@
 @pytest.mark.mypy
 @pytest.mark.linter
 def test_mypy():
+    try:
+        import importlib.resources as _
+    except ModuleNotFoundError:
+        # The importlib_resources package is a backport of the importlib.resources module
+        # from Python 3.9. The 'policy' module of this project first tries to import from
+        # importlib.resources, then falls back to the backport package.
+        # There is a bug in mypy that manifests when this try/except import pattern is
+        # used: https://github.com/python/mypy/issues/1153
+        pytest.skip('This platform does not support mypy checking of importlib properly')
     assert main(argv=[]) == 0, 'Found errors'