StopIteration Runtime Exception with Python 3.8

[jazzdup]

`2021-04-22 07:36:48,231 [CRITICAL] mongo_connector.oplog_manager:713 - Exception during collection dump
Traceback (most recent call last):
File "/home/al/dev/zapper/projects/etl2/lib/python3.8/site-packages/mongo_connector/doc_managers/solr_doc_manager.py", line 292, in
batch = list(next(cleaned) for i in range(self.chunk_size))
StopIteration

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/home/al/dev/zapper/projects/etl2/lib/python3.8/site-packages/mongo_connector/oplog_manager.py", line 668, in do_dump
upsert_all(dm)
File "/home/al/dev/zapper/projects/etl2/lib/python3.8/site-packages/mongo_connector/oplog_manager.py", line 651, in upsert_all
dm.bulk_upsert(docs_to_dump(from_coll), mapped_ns, long_ts)
File "/home/al/dev/zapper/projects/etl2/lib/python3.8/site-packages/mongo_connector/util.py", line 33, in wrapped
return f(*args, **kwargs)
File "/home/al/dev/zapper/projects/etl2/lib/python3.8/site-packages/mongo_connector/doc_managers/solr_doc_manager.py", line 292, in bulk_upsert
batch = list(next(cleaned) for i in range(self.chunk_size))
RuntimeError: generator raised StopIteration
2021-04-22 07:36:48,232 [ERROR] mongo_connector.oplog_manager:723 - OplogThread: Failed during dump collection cannot recover!`

code fix is in solr_doc_manager.py, replace 2x instances of:
batch = list(next(cleaned) for i in range(self.chunk_size))
with
batch = [] for i in range(self.chunk_size): for x in cleaned: batch.append(x)