File "trezorlib/client.py", line 107, in cancel
  File "trezorlib/client.py", line 127, in _raw_write
  File "trezorlib/transport/bridge.py", line 159, in write
  File "trezorlib/transport/bridge.py", line 68, in write_buf
  File "trezorlib/transport/bridge.py", line 135, in _call
  File "trezorlib/transport/bridge.py", line 44, in call_bridge