cbworkloadgen throws list index out of range error - breaks build sanity

[root@node1-mad-hatter-testing-centos7 ~]# /opt/couchbase/bin/cbworkloadgen -n 10.112.194.101:8091 -u Administrator -p 'password' -j -i 1000 -b default

Exception in thread s0:

Traceback (most recent call last):

  File "/opt/couchbase/lib/python/runtime/lib/python3.7/threading.py", line 917, in _bootstrap_inner

    self.run()

  File "/opt/couchbase/lib/python/runtime/lib/python3.7/threading.py", line 865, in run

    self._target(*self._args, **self._kwargs)

  File "/opt/couchbase/lib/python/pump_mc.py", line 112, in run

    rv, batch, need_backoff = self.scatter_gather(mconns, batch)

  File "/opt/couchbase/lib/python/pump_cb.py", line 104, in scatter_gather

    rv, retry, refresh = self.recv_msgs(conn, msgs, skipped, vbucket_id=vbucket_id)

  File "/opt/couchbase/lib/python/pump_mc.py", line 427, in recv_msgs

    if i == skipped[0]:

IndexError: list index out of range

[root@node1-mad-hatter-testing-centos7 ~]# /opt/couchbase/bin/cbworkloadgen -n 10.112.194.101:8091 -u Administrator -p 'password' -j -i 1000 -b default

  [####################] 100.0% (1053/estimated 1053 msgs)

bucket: default, msgs transferred...

       :                total |       last |    per sec

 byte  :                70107 |      70107 |  1155707.3

done