[Bug]: [Jupyter] TypeError: the JSON object must be str, bytes or bytearray, not NoneType

[neubig]

Is there an existing issue for the same bug?

• I have checked the existing issues.

Describe the bug and reproduction steps

I got the following error during an OpenHands session:

Let me try to fix the JSON manually:

Editing the contents of a file

500 Server Error: Internal Server Error for url: https://nuewalpbouzhlewc.prod-runtime.all-hands.dev/execute_action Details: Traceback (most recent call last): File "/openhands/code/openhands/runtime/action_execution_server.py", line 525, in execute_action observation = await client.run_action(action) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/code/openhands/runtime/action_execution_server.py", line 182, in run_action observation = await getattr(self, action_type)(action) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/code/openhands/runtime/action_execution_server.py", line 216, in run_ipython obs: IPythonRunCellObservation = await _jupyter_plugin.run(action) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/code/openhands/runtime/plugins/jupyter/init.py", line 80, in run obs = await self._run(action) ^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/code/openhands/runtime/plugins/jupyter/init.py", line 73, in _run output = await self.kernel.execute(action.code, timeout=action.timeout) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/asyncio/init.py", line 189, in async_wrapped return await copy(fn, *args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/asyncio/init.py", line 111, in call do = await self.iter(retry_state=retry_state) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/asyncio/init.py", line 153, in iter result = await action(retry_state) ^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/_utils.py", line 99, in inner return call(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/init.py", line 398, in <lambda> self._add_action_func(lambda rs: rs.outcome.result()) ^^^^^^^^^^^^^^^^^^^ File "/openhands/micromamba/envs/openhands/lib/python3.12/concurrent/futures/_base.py", line 449, in result return self.__get_result() ^^^^^^^^^^^^^^^^^^^ File "/openhands/micromamba/envs/openhands/lib/python3.12/concurrent/futures/_base.py", line 401, in __get_result raise self._exception File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tenacity/asyncio/init.py", line 114, in call result = await fn(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/code/openhands/runtime/plugins/jupyter/execute_server.py", line 220, in execute execution_done = await asyncio.wait_for(wait_for_messages(), timeout) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/openhands/micromamba/envs/openhands/lib/python3.12/asyncio/tasks.py", line 520, in wait_for return await fut ^^^^^^^^^ File "/openhands/code/openhands/runtime/plugins/jupyter/execute_server.py", line 180, in wait_for_messages msg = json_decode(msg) ^^^^^^^^^^^^^^^^ File "/openhands/poetry/openhands-ai-5O4_aCHf-py3.12/lib/python3.12/site-packages/tornado/escape.py", line 104, in json_decode return json.loads(value) ^^^^^^^^^^^^^^^^^ File "/openhands/micromamba/envs/openhands/lib/python3.12/json/init.py", line 339, in loads raise TypeError(f'the JSON object must be str, bytes or bytearray, ' TypeError: the JSON object must be str, bytes or bytearray, not NoneType

OpenHands Installation

app.all-hands.dev

OpenHands Version

0.19.0

Operating System

None

Logs, Errors, Screenshots, and Additional Context

No response

[enyst]

Looks like it's in the Jupyter plugin, msg was None:

jupyter/execute_server.py", line 180, in wait_for_messages msg = json_decode(msg)

[neubig]

@openhands-agent : please examine the circumstances under which this error could occur, and propose a fix if possible.

[openhands-agent]

OpenHands started fixing the issue! You can monitor the progress here.