_cb.Peripheral.write_characteristic_value raises SystemError

[o-murphy]

I'm developing the bleak-compatible backend based on built-in _cb module. It is almost done, discover, connection, notifying and value reading works, but in the end I encountered an unexpected problem, it looks like _cb.Peripheral. write_characteristic_value(...) has a C-level bug that raises SystemError: PY_SSIZE_T_CLEAN macro must be defined for '#' formats

Just try

import cb

cb.Peripheral().write_characteristic_value(cb.Characteristic(), b"", 0)


Traceback (most recent call last):
  File "<string>", line 1, in <module>
SystemError: PY_SSIZE_T_CLEAN macro must be defined for '#' formats

self.client.write_gatt_char(
  File "/private/var/mobile/Containers/Shared/AppGroup/FE817F0D-F288-48F8-A509-E7559374B783/Pythonista3/Documents/site-packages/bleak/__init__.py", line 723, in write_gatt_char
    await self._backend.write_gatt_char(characteristic, data, response)
  File "/private/var/mobile/Containers/Shared/AppGroup/FE817F0D-F288-48F8-A509-E7559374B783/Pythonista3/Documents/site-packages/bleak_pythonista/backend/pythonistacb/client.py", line 278, in write_gatt_char
    await self._delegate.write_characteristic(
  File "/private/var/mobile/Containers/Shared/AppGroup/FE817F0D-F288-48F8-A509-E7559374B783/Pythonista3/Documents/site-packages/bleak_pythonista/backend/pythonistacb/CentralManager.py", line 475, in write_characteristic
    p.write_characteristic_value(c, value, with_response)
SystemError: PY_SSIZE_T_CLEAN macro must be defined for '#' formats

[tbmuc25]

Encountered the same problem. Hope a fix will be coming soon!