Log threading exceptions properly (#34789)

homeassistant/bootstrap.py

@@ -249,6 +249,10 @@ def async_enable_logging(
     logging.getLogger("urllib3").setLevel(logging.WARNING)
     logging.getLogger("aiohttp.access").setLevel(logging.WARNING)
 
+    sys.excepthook = lambda *args: logging.getLogger(None).exception(
+        "Uncaught exception", exc_info=args  # type: ignore
+    )
+
     # Log errors to a file if we have write access to file or config dir
     if log_file is None:
         err_log_path = hass.config.path(ERROR_LOG_FILENAME)

homeassistant/core.py

@@ -71,6 +71,7 @@ from homeassistant.exceptions import (
 from homeassistant.util import location
 from homeassistant.util.async_ import fire_coroutine_threadsafe, run_callback_threadsafe
 import homeassistant.util.dt as dt_util
+from homeassistant.util.thread import fix_threading_exception_logging
 from homeassistant.util.unit_system import IMPERIAL_SYSTEM, METRIC_SYSTEM, UnitSystem
 
 # Typing imports that create a circular dependency
@@ -80,6 +81,7 @@ if TYPE_CHECKING:
 
 
 block_async_io.enable()
+fix_threading_exception_logging()
 
 # pylint: disable=invalid-name
 T = TypeVar("T")

homeassistant/util/thread.py

@@ -0,0 +1,26 @@
+"""Threading util helpers."""
+import sys
+import threading
+from typing import Any
+
+
+def fix_threading_exception_logging() -> None:
+    """Fix threads passing uncaught exceptions to our exception hook.
+
+    https://bugs.python.org/issue1230540
+    Fixed in Python 3.8.
+    """
+    if sys.version_info[:2] >= (3, 8):
+        return
+
+    run_old = threading.Thread.run
+
+    def run(*args: Any, **kwargs: Any) -> None:
+        try:
+            run_old(*args, **kwargs)
+        except (KeyboardInterrupt, SystemExit):  # pylint: disable=try-except-raise
+            raise
+        except Exception:  # pylint: disable=broad-except
+            sys.excepthook(*sys.exc_info())
+
+    threading.Thread.run = run  # type: ignore