MQ submission failed

Ego4D Challenges
1

The test code failed with the following error:

Traceback (most recent call last):
  File "/code/scripts/workers/submission_worker.py", line 504, in run_submission
    submission_metadata=submission_serializer.data,
  File "/tmp/tmpcijue36f/compute/challenge_data/challenge_1626/main.py", line 47, in evaluate
    _, detection_avg_mAP = get_det_accuracy(test_annotation_file, user_submission_file)
  File "/tmp/tmpcijue36f/compute/challenge_data/challenge_1626/eval_detection.py", line 290, in get_det_accuracy
    mAPs, average_mAP = anet_detection.evaluate()
  File "/tmp/tmpcijue36f/compute/challenge_data/challenge_1626/eval_detection.py", line 185, in evaluate
    self.ap = self.wrapper_compute_average_precision()
  File "/tmp/tmpcijue36f/compute/challenge_data/challenge_1626/eval_detection.py", line 164, in wrapper_compute_average_precision
    ) for label_name, cidx in self.activity_index.items())
  File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 1085, in __call__
    if self.dispatch_one_batch(iterator):
  File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 901, in dispatch_one_batch
    self._dispatch(tasks)
  File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 819, in _dispatch
    job = self._backend.apply_async(batch, callback=cb)
  File "/usr/local/lib/python3.7/site-packages/joblib/_parallel_backends.py", line 556, in apply_async
    future = self._workers.submit(SafeFunction(func))
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/reusable_executor.py", line 176, in submit
    return super().submit(fn, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/process_executor.py", line 1149, in submit
    self._ensure_executor_running()
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/process_executor.py", line 1123, in _ensure_executor_running
    self._adjust_process_count()
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/process_executor.py", line 1111, in _adjust_process_count
    p.start()
  File "/usr/local/lib/python3.7/multiprocessing/process.py", line 112, in start
    self._popen = self._Popen(self)
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/backend/process.py", line 32, in _Popen
    return Popen(process_obj)
  File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/backend/popen_loky_posix.py", line 42, in __init__
    sys.stdout.flush()
AttributeError: 'MultiOut' object has no attribute 'flush'

This seems like a bug on the server side as the same json file was processed successfully in the past.