celeryonce stacktrace

      [2020-02-13 20:11:45,652: WARNING/ForkPoolWorker-2] GET EVENTS task has been called now
      [2020-02-13 20:11:45,706: WARNING/ForkPoolWorker-1] /usr/local/lib/python3.6/site-packages/celery/app/trace.py:561: RuntimeWarning: Exception raised outside body: FileNotFoundError(2, 'No such file or directory'):
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_52094e3196ca05f36eb013e2b749ce03'

        exc, exc_info.traceback)))
      [2020-02-13 20:11:45,750: ERROR/ForkPoolWorker-1] Task apimb.tasks.get_balance[6af923d7-f1a1-451a-bc8d-e4f07f3b2f06] raised unexpected: FileNotFoundError(2, 'No such file or directory')
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_52094e3196ca05f36eb013e2b749ce03'
      [2020-02-13 20:11:45,813: WARNING/ForkPoolWorker-1] GET ORDERS task has been called now
      [2020-02-13 20:11:45,860: INFO/ForkPoolWorker-1] Task apimb.tasks.get_orders[3c30ddee-22a2-4831-b256-0511ed1b8cc6] succeeded in 0.10413699999844539s: None
      [2020-02-13 20:11:45,875: WARNING/ForkPoolWorker-1] /usr/local/lib/python3.6/site-packages/celery/app/trace.py:561: RuntimeWarning: Exception raised outside body: FileNotFoundError(2, 'No such file or directory'):
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_55d76a4bebdad047aea38a8fd7e07c8e'

        exc, exc_info.traceback)))
      [2020-02-13 20:11:45,937: ERROR/ForkPoolWorker-1] Task apimb.tasks.get_orders[3c30ddee-22a2-4831-b256-0511ed1b8cc6] raised unexpected: FileNotFoundError(2, 'No such file or directory')
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_55d76a4bebdad047aea38a8fd7e07c8e'
      [2020-02-13 20:11:48,857: INFO/ForkPoolWorker-2] Task apimb.tasks.get_events[b423ad7e-cf2b-4137-8f2d-25bb934dc148] succeeded in 3.861357500001759s: None
      [2020-02-13 20:11:48,878: WARNING/ForkPoolWorker-2] /usr/local/lib/python3.6/site-packages/celery/app/trace.py:561: RuntimeWarning: Exception raised outside body: FileNotFoundError(2, 'No such file or directory'):
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_f98116d19c287c5287360c9ef915d089'

        exc, exc_info.traceback)))
      [2020-02-13 20:11:48,910: ERROR/ForkPoolWorker-2] Task apimb.tasks.get_events[b423ad7e-cf2b-4137-8f2d-25bb934dc148] raised unexpected: FileNotFoundError(2, 'No such file or directory')
      Traceback (most recent call last):
        File "/usr/local/lib/python3.6/site-packages/celery/app/trace.py", line 465, in trace_task
          state, retval, uuid, args, kwargs, None,
        File "/usr/local/lib/python3.6/site-packages/celery_once/tasks.py", line 141, in after_return
          self.once_backend.clear_lock(key)
        File "/usr/local/lib/python3.6/site-packages/celery_once/backends/file.py", line 76, in clear_lock
          os.remove(lock_path)
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/celery_once/qo_apimb.tasks.ge_f98116d19c287c5287360c9ef915d089