File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/electrum/plugin.py", line 362, in wrapper
    return run_in_hwd_thread(partial(func, *args, **kwargs))
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/electrum/plugin.py", line 355, in run_in_hwd_thread
    return fut.result()
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/concurrent/futures/_base.py", line 435, in result
    return self.__get_result()
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/electrum/plugins/keepkey/clientbase.py", line 162, in cancel
    self.transport.write(self.proto.Cancel())
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/keepkeylib/transport.py", line 69, in write
    self._write(b"##" + header + ser, msg)
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/keepkeylib/transport_webusb.py", line 115, in _write
    self.handle.interruptWrite(self.endpoint, [63, ] + list(msg[:63]) + [0] * (63 - len(msg[:63])))
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/usb1/__init__.py", line 1472, in interruptWrite
    return self._interruptTransfer(endpoint, data, sizeof(data), timeout)
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/usb1/__init__.py", line 1444, in _interruptTransfer
    timeout,
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/usb1/__init__.py", line 127, in mayRaiseUSBError
    __raiseUSBError(value)
  File "/tmp/.mount_electrlKpMwZ/usr/lib/python3.7/site-packages/usb1/__init__.py", line 119, in raiseUSBError
    raise __STATUS_TO_EXCEPTION_DICT.get(value, __USBError)(value)