diff --git a/api/command.py b/api/command.py
index e48a732..82d72fb 100644
--- a/api/command.py
+++ b/api/command.py
@@ -271,8 +271,11 @@ def execute_delete_command(name: str, cs: ChangeSet) -> ChangeSet:
 def execute_batch_commands(name: str, cs: ChangeSet) -> ChangeSet:
     result = ChangeSet()
 
+    todo = {}
+
     try:
         for op in cs.operations:
+            todo = op
             operation = op['operation']
             if operation == API_ADD:
                 result.merge(execute_add_command(name, ChangeSet(op)))
@@ -281,6 +284,7 @@ def execute_batch_commands(name: str, cs: ChangeSet) -> ChangeSet:
             elif operation == API_DELETE:
                 result.merge(execute_delete_command(name, ChangeSet(op)))
     except:
+        print(f'ERROR: Fail to execute {todo}!')
         pass
 
     return result