Aubio.source args can be wrong

[yomguy]

Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/celery/app/trace.py", line 385, in trace_task
R = retval = fun(*args, *kwargs)
File "/usr/local/lib/python3.7/dist-packages/celery/app/trace.py", line 650, in __protected_call__
return self.run(args, **kwargs)
File "/srv/lib/timeside/timeside/server/tasks.py", line 39, in experience_run
item.run(experience)
File "/srv/lib/timeside/timeside/server/models.py", line 487, in run
sha1=self.sha1
File "/srv/lib/timeside/timeside/plugins/decoder/aubio.py", line 22, in init
self.source = aubio.source(self.uri, hop_size=self.output_blocksize)
TypeError: argument 1 must be str, not None