[fix] fix detach_output_obj clone;

colossalai/pipeline/schedule/zero_bubble_pp.py

@@ -622,10 +622,10 @@ class ZeroBubbleVPipeScheduler(PipelineSchedule):
         else:
             # detach output
             detached_output_obj = tree_map(detach, output_obj)
-        # 3-2 clone output
-        output_obj = tree_map(clone, output_obj)
+            # 3-2 clone detached_output_obj
+            detached_output_obj = tree_map(clone, detached_output_obj)
+
         # 3-3 release cloned output.data; release_tensor_data output for bwd b & w; (do not detach output)
-        # output_obj = tree_map(clone, output_obj)
         if model_chunk_id == 1 and self.stage_manager.is_first_stage(ignore_chunk=True):
             # We should not release_tensor_data bwd LOSS
             pass