python runtime_error ai_generated partial

Exception in background task: RuntimeError: Event loop is closed

ID: python/starlette-background-task-exception

Also available as: JSON · Markdown · 中文
80%Fix Rate
83%Confidence
0Evidence
2024-11-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

A BackgroundTask attempts to use the event loop after the response is sent and the loop is torn down, often in tests or when using loop.run_until_complete.

generic

中文

BackgroundTask 在响应发送后、事件循环拆除后尝试使用事件循环，常见于测试或使用 loop.run_until_complete 时。

Workarounds

  1. 90% success 
    Use httpx.AsyncClient with ASGITransport in tests to keep loop alive
  2. 82% success 
    Prefer sync def background tasks for I/O that must complete after response

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Loop is already closed; cannot recover.

  2. 70% fail

    Same closed-loop issue in test environments.