Subtle issue with scanning... it is possible that there is a race condition.

Traceback (most recent call last):
File "scan_waterfall.py", line 80, in
sw.collect_data()
File "scan_waterfall.py", line 74, in collect_data
scan_results = hw.scan()
File "", line 2, in scan
File "/Users/leekkizogloy/arch/env/py27/lib/python2.7/site-packages/typedargs/utils.py", line 34, in _check_and_execute
retval = func(*convargs, **convkw)
File "/Users/leekkizogloy/arch/env/py27/lib/python2.7/site-packages/iotile/core/hw/hwmanager.py", line 891, in scan
devices = self.stream.scan(wait=wait)
File "/Users/leekkizogloy/arch/env/py27/lib/python2.7/site-packages/iotile/core/hw/transport/cmdstream.py", line 115, in scan
return sorted(self._scan(wait=wait), key=lambda x: x['uuid'])
File "/Users/leekkizogloy/arch/env/py27/lib/python2.7/site-packages/iotile/core/hw/transport/adapterstream.py", line 110, in _scan
for name, value in viewitems(self._scanned_devices):
RuntimeError: dictionary changed size during iteration