Bug Report: Blocking call to import_module in event loop causing stability issues

[zoesn89]

Bug Report: Blocking call to import_module in event loop causing stability issues

Description

Home Assistant detects a blocking import_module call in the event loop that is causing stability issues. The call occurs when loading the pyscript custom component.

Environment

• Home Assistant Version: 2026.1.0
• Python Version: 3.13
• Affected Integration: pyscript (Custom Component)
• Installation Type: Home Assistant OS

Error Log

Detected blocking call to import_module with args ('custom_components.pyscript',) in 
/usr/src/homeassistant/homeassistant/loader.py, line 1078: 
ComponentProtocol, importlib.import_module(self.pkg_path) inside the event loop; 
This is causing stability issues.

Full Traceback

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/usr/src/homeassistant/homeassistant/__main__.py", line 229, in <module>
    sys.exit(main())
  File "/usr/src/homeassistant/homeassistant/__main__.py", line 215, in main
    exit_code = runner.run(runtime_conf)
  File "/usr/src/homeassistant/homeassistant/runner.py", line 289, in run
    return loop.run_until_complete(setup_and_run_hass(runtime_config))
  File "/usr/local/lib/python3.13/asyncio/base_events.py", line 712, in run_until_complete
    self.run_forever()
  File "/usr/local/lib/python3.13/asyncio/base_events.py", line 683, in run_forever
    self._run_once()
  File "/usr/local/lib/python3.13/asyncio/base_events.py", line 2050, in _run_once
    handle._run()
  File "/usr/local/lib/python3.13/asyncio/events.py", line 89, in _run
    self._context.run(self._callback, *self._args)
  File "/usr/src/homeassistant/homeassistant/setup.py", line 170, in async_setup_component
    result = await _async_setup_component(hass, domain, config)
  File "/usr/src/homeassistant/homeassistant/setup.py", line 343, in _async_setup_component
    component = await integration.async_get_component()
  File "/usr/src/homeassistant/homeassistant/loader.py", line 1030, in async_get_component
    comp = self._get_component()
  File "/usr/src/homeassistant/homeassistant/loader.py", line 1078, in _get_component
    ComponentProtocol, importlib.import_module(self.pkg_path)

Problem

The importlib.import_module() call is executed synchronously within the async event loop, leading to blocking I/O operations that compromise Home Assistant's stability.

Expected Behavior

The import should be performed asynchronously or in a separate thread to avoid blocking the event loop.

Reproducibility

• Occurs during Home Assistant startup
• Happens when loading the pyscript custom component
• Reproducible on every restart with the pyscript integration installed

Additional Information

• Reference to Developer Documentation: https://developers.home-assistant.io/docs/asyncio_blocking_operations/#import_module
• Affected file: /usr/src/homeassistant/homeassistant/loader.py, line 1078
• The issue appears to be related to Python 3.13 and its stricter asyncio checks

Possible Solution

The import should be offloaded to an executor using await hass.async_add_executor_job() or a similar mechanism to prevent blocking the event loop.

[craigbarratt]

Pyscript itself isn't calling import_module in the event loop. Your pyscript scripts are the cause, either directly or indirectly (eg, lazy loading modules like pytz). What modules are used in your scripts?

[zoesn89]

Pyscript itself isn't calling import_module in the event loop. Your pyscript scripts are the cause, either directly or indirectly (eg, lazy loading modules like pytz). What modules are used in your scripts?

Hey, thanks for the quick reply ;)
I'm using the following modules: requests, json, datetime, zoneinfo, traceback.

[craigbarratt]

Several of the requests methods (eg: requests.get) are blocking. Not sure if that is the issue though. See the docs.

[zoesn89]

Ok, this is not the problem, as it seems. After I updated HA to 2026.1.0 today, pyscript isn't working anymore. Now I have a new error:
Setup failed for custom integration 'pyscript': Unable to import component: cannot import name 'Config' from 'homeassistant.core' (/usr/src/homeassistant/homeassistant/core.py) ... ImportError: cannot import name 'Config' from 'homeassistant.core' (/usr/src/homeassistant/homeassistant/core.py). Did you mean: 'config'?

[zoesn89]

ok, a fresh new installation worked. Thanks for your help!