Applies utf-8 encoding to batch_string before creating an md5 hash

luigi/scheduler.py

@@ -942,7 +942,8 @@ def get_work(self, host=None, assistant=False, current_tasks=None, worker=None,
  'n_unique_pending': n_unique_pending}
 
  if len(batched_tasks) > 1:
- batch_id = hashlib.md5('|'.join(task.id for task in batched_tasks)).hexdigest()
+ batch_string = '|'.join(task.id for task in batched_tasks)
+ batch_id = hashlib.md5(batch_string.encode('utf-8')).hexdigest()
  for task in batched_tasks:
  self._state.set_batch_running(task, batch_id, worker_id)