UnboundLocalError: cannot access local variable 'tracer_output' where it is not a ssociated with a value

[zou3519]

(Worker_TP1 pid=243560) ERROR 11-07 10:44:16 [multiproc_executor.py:699] if tracer_output:
(Worker_TP1 pid=243560) ERROR 11-07 10:44:16 [multiproc_executor.py:699] ^^^^^^^^^^^^^
(Worker_TP1 pid=243560) ERROR 11-07 10:44:16 [multiproc_executor.py:699] UnboundLocalError: cannot access local variable 'tracer_output' where it is not associated with a value

Only in 2.9.0. Can we fix for 2.9.1?

https://github.com/pytorch/pytorch/blame/release/2.9/torch/_dynamo/convert_frame.py#L1473

cc @chauhang @penguinwu

[zou3519]

need to cherry-pick #163169 to release branch

[atalman]

Cherry-Picked. Closing this issue