py_gen/utils: more specific error msg
diff --git a/py_gen/util.py b/py_gen/util.py
index 068a234..30c5d50 100644
--- a/py_gen/util.py
+++ b/py_gen/util.py
@@ -71,7 +71,7 @@
elif type_maps.table_feature_prop_is_extension(cls, version):
return type_maps.type_val[("of_table_feature_prop_experimenter", version)]
else:
- raise ValueError
+ raise ValueError("No wiretype for %s in version %d" % (cls, version))
def constant_for_value(version, group, value):
return (["const." + v["ofp_name"] for k, v in of_g.identifiers.items()