Error in learn function

[paulearley]

I installed your promising Broadlink app on an otherwise empty Pi3 running docker. I discovered my BroadLink Pro fine. Then an error occurred: failure to learn. Steps to reproduce:

1. Click the plus sign next to commands.
2. Prompted to press command button
3. This error was reported in the pi login:
   Traceback (most recent call last):
   File "/usr/local/lib/python3.11/site-packages/flask/app.py", line 2447, in wsgi_app
   response = self.full_dispatch_request()
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/app.py", line 1952, in full_dispatch_request
   rv = self.handle_user_exception(e)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask_cors/extension.py", line 194, in wrapped_function
   return cors_after_request(app.make_response(f(*args, **kwargs)))
   ^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/app.py", line 1821, in handle_user_exception
   reraise(exc_type, exc_value, tb)
   File "/usr/local/lib/python3.11/site-packages/flask/_compat.py", line 39, in reraise
   raise value
   File "/usr/local/lib/python3.11/site-packages/flask/app.py", line 1950, in full_dispatch_request
   rv = self.dispatch_request()
   ^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/app.py", line 1936, in dispatch_request
   return self.view_functionsrule.endpoint
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/app/./api.py", line 68, in learn
   return jsonify(learn_command(ip_address, command_name, host_ip))
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/json/init.py", line 370, in jsonify
   dumps(data, indent=indent, separators=separators) + "\n",
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/json/init.py", line 211, in dumps
   rv = _json.dumps(obj, **kwargs)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/json/init.py", line 238, in dumps
   **kw).encode(obj)
   ^^^^^^^^^^^
   File "/usr/local/lib/python3.11/json/encoder.py", line 200, in encode
   chunks = self.iterencode(o, _one_shot=True)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/json/encoder.py", line 258, in iterencode
   return _iterencode(o, 0)
   ^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/site-packages/flask/json/init.py", line 100, in default
   return _json.JSONEncoder.default(self, o)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/local/lib/python3.11/json/encoder.py", line 180, in default
   raise TypeError(f'Object of type {o.class.name} '
   TypeError: Object of type Exception is not JSON serializable

I do very little python programming, could you look into this?
Paul Earley