TST: mark xfail

unittests/test_macros.py

@@ -410,6 +410,10 @@ SimulationData:
     #     f.write(yaml.dump(cfood))
 
 
+@pytest.mark.xfail(
+    reason="Wait until this feature is implemented"
+    "https://gitlab.com/caosdb/caosdb-crawler/-/issues/21."
+)
 def test_def_replacements():
     """Test that parameters in macro definitions can be used
     for defining subsequent parameters.