This repo is meant to reproduce an error while running an asynchronous chronometer in Streamlit.
Running this code locally works fine while the deployed version on Streamlit Cloud does not.
It can be found at chronometer.py.
Go to the deployed version:
Then follow these steps:
- Click on "Start" button
- Click on "Stop" button
- Click on "Save" or "Delete" buttons
- Click on "Start" button again
- Click on "Stop" button again
The following error message will pop up:
Traceback (most recent call last):
File "/home/appuser/venv/lib/python3.10/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 565, in _run_script
exec(code, module.__dict__)
File "/app/streamlit-chronometer/chronometer.py", line 78, in <module>
asyncio.run(run_chronometer(container))
File "/usr/local/lib/python3.10/asyncio/runners.py", line 44, in run
return loop.run_until_complete(main)
File "/usr/local/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
return future.result()
File "/app/streamlit-chronometer/chronometer.py", line 14, in run_chronometer
while st.session_state["chrono_running"] and run_time < MAX_TIME - TIMESTEP_REAL:
File "/home/appuser/venv/lib/python3.10/site-packages/streamlit/runtime/state/session_state_proxy.py", line 90, in __getitem__
return get_session_state()[key]
File "/home/appuser/venv/lib/python3.10/site-packages/streamlit/runtime/state/safe_session_state.py", line 104, in __getitem__
raise KeyError(key)
KeyError: 'chrono_running'
And the stop time will always fail to be captured from now on.
- Streamlit version: 1.19
- Python version: 3.10
- Operating System: Windows
If you try to use streamlit==1.20+, you would obtain the same error locally as well. I found out this is due to the fastReruns default value which has become true in these releases. If you overwrite the value to false within .streamlit/config.toml file, you would solve the problem locally but it will persist on the deployed version. Using streamlit==1.19 overcomes this problem.