Traceback (most recent call last):


 "/home/mypc/.local/bin/flow", line 6, in <module>

cliHandler(sys.argv)


 "/home/mypc/.local/lib/python2.7/site-packages/darkflow/cli.py", line 29, in cliHandler

print('Enter training ...'); tfnet.train()


 "/home/mypc/.local/lib/python2.7/site-packages/darkflow/net/flow.py", line 39, in train

for i, (x_batch, datum) in enumerate(batches):


 "/home/mypc/.local/lib/python2.7/site-packages/darkflow/net/yolo/data.py", line 126, in shuffle

x_batch = np.concatenate(x_batch, 0)
ValueError: need at least one array to concatenate

Traceback (most recent call last):


 "/usr/local/lib/python3.6/site-packages/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py", line 491, in _thread_main

response = self._bidi_rpc.recv()


 "/usr/local/lib/python3.6/site-packages/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py", line 404, in recv

super(ResumableBidiRpc, self).recv)


 "/usr/local/lib/python3.6/site-packages/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py", line 393, in _recoverable

raise exc


 "/usr/local/lib/python3.6/site-packages/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py", line 385, in _recoverable

return method(*args, **kwargs)


 "/usr/local/lib/python3.6/site-packages/google/cloud/pubsub_v1/subscriber/_protocol/bidi.py", line 258, in recv

'Can not recv() on an RPC that has never been open()ed.')
ValueError: Can not recv() on an RPC that has never been open()ed."

