Using BleakClient's unpair() causes crash

• bleak version: 0.14.2
• Python version: 3.10.1
• Operating System: Windows 11 Pro, version: 21H2
• BlueZ version (bluetoothctl -v) in case of Linux:

Description

My program connects to a device writes/reads some characteristics and then disconnects. After some seconds the procedure repeats. I am getting the following error message after running the application for some minutes, if I am using the BleakClient’s unpair() function before disconnection - actually this function causes disconnection itself. If the the unpair() function is not called just the disconnect() the issue does not pop up.

Exception has occurred: CancelledError
exception: no description
  File "C:\Users\andras.kalmar\BLE_assistant\ccis-assistant-pythonble-33867\src\main.py", line 90, in scanner_loop
    success = await bleClient.connect(unit_id=key)
  File "C:\Users\andras.kalmar\BLE_assistant\ccis-assistant-pythonble-33867\src\main\tssbleclient\tss_ble_client.py", line 634, in connect
    await self.ble_client.connect(timeout=self.CONNECT_TIMEOUT)
  File "C:\Users\andras.kalmar\AppData\Roaming\Python\Python310\site-packages\bleak\backends\winrt\client.py", line 276, in connect
    await self.get_services()
  File "C:\Users\andras.kalmar\AppData\Roaming\Python\Python310\site-packages\bleak\backends\winrt\client.py", line 467, in get_services
    await self._requester.get_gatt_services_async(

During handling of the above exception, another exception occurred:

  File "C:\Program Files\Python_3_1_0\Lib\asyncio\base_events.py", line 641, in run_until_complete
    return future.result()
  File "C:\Program Files\Python_3_1_0\Lib\asyncio\runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "C:\Users\andras.kalmar\BLE_assistant\ccis-assistant-pythonble-33867\src\main.py", line 57, in scanner_loop_async
    asyncio.run(scanner_loop())
  File "C:\Users\andras.kalmar\BLE_assistant\ccis-assistant-pythonble-33867\src\main.py", line 287, in <lambda>
    threading.Thread(target=lambda: scanner_loop_async()).start()
  File "C:\Program Files\Python_3_1_0\Lib\threading.py", line 946, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Program Files\Python_3_1_0\Lib\threading.py", line 1009, in _bootstrap_inner
    self.run()
  File "C:\Program Files\Python_3_1_0\Lib\threading.py", line 966, in _bootstrap
    self._bootstrap_inner()

[dlech]

Constantly connecting and disconnecting without any delay seems like it is asking for trouble in the OS Bluetooth stack. We also don’t recommend reusing the same BleakClient object after disconnecting since it will be in an inconsistent state.

[andraskalmar]

I think I have found the solution to this problem.

The problem was that asyncio.CancelledError is not a subclass of Exception but a subclass of BaseException, thus the exception was not handled. I added except asyncio.CancelledError as e: into the exception handlings and the program continued to work after the exception happened.

I think it could be useful to add this into the Bleak examples or into the Readme.