test tree foreach

spike/review/reinvent/ezmded/server/server.go

@@ -499,7 +499,7 @@ func (server *Server) _apiV0SearchHandler(query string) ([][2]string, error) {
 		result = append(result, [2]string{id.URLSafeString(), title})
 		return nil
 	}); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed for each: %v", err)
 	}
 	return result, nil
 }