Log owner groups which are non-public and members can't be listed

This facilitates making these groups public.

Change-Id: I27ee7d740992e70fcbc6bf19f9cdf9911079893d
diff --git a/tools/plugins.py b/tools/plugins.py
index 16c0998..88cc6b2 100644
--- a/tools/plugins.py
+++ b/tools/plugins.py
@@ -217,7 +217,7 @@
 
             parent, owner_group_ids = self._get_meta_data(name)
             maintainers, maintainers_csv = self._get_owner_names(
-                parent, owner_group_ids
+                parent, name, owner_group_ids
             )
             self.plugins.append(
                 Plugin(
@@ -304,7 +304,8 @@
             owner_group_ids = list()
         return parent, owner_group_ids
 
-    def _get_owner_names(self, parent, owner_group_ids):
+    def _get_owner_names(self, parent, name, owner_group_ids):
+        names = set()
         accounts = set()
         external_groups = set()
         all_owner_group_ids = set(owner_group_ids)
@@ -318,8 +319,10 @@
                     for s in subgroups:
                         all_owner_group_ids.add(s.get("id"))
                 except requests.HTTPError:
-                    # can't read group
-                    pass
+                    print(
+                        f"Failed to read subgroup {id} of owner group of plugin {name}",
+                        file=sys.stderr,
+                    )
         for id in all_owner_group_ids:
             try:
                 if id == CORE_MAINTAINERS_ID:
@@ -332,8 +335,9 @@
                     }
                     accounts.update(a)
             except requests.HTTPError:
-                # can't read group
-                pass
+                print(
+                    f"Failed to read owner group {id} of plugin {name}", file=sys.stderr
+                )
         names = sorted({a.name for a in accounts} | external_groups)
         csv = ", ".join(names)
         return accounts, csv