File "trezorlib/client.py", line 98, in cancel
  File "trezorlib/client.py", line 107, in _raw_write
  File "trezorlib/transport/bridge.py", line 168, in write
  File "trezorlib/transport/bridge.py", line 72, in write_buf
  File "trezorlib/transport/bridge.py", line 136, in _call
  File "trezorlib/transport/bridge.py", line 49, in call_bridge