python install_error ai_generated true

async def functions are not natively supported. You need to install a suitable plugin for your async framework, for example: - anyio - pytest-asyncio

ID: python/pytest-asyncio-not-installed

Also available as: JSON · Markdown · 中文
80%Fix Rate
90%Confidence
0Evidence
2024-02-08First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.x active — — —
8.x active — — —

Root Cause

Pytest cannot run `async def` test functions without an async plugin. The test is collected but pytest refuses to execute it because the event loop is not managed.

generic

中文

在没有异步插件的情况下，pytest 无法运行 `async def` 测试函数。测试会被收集，但 pytest 拒绝执行，因为没有管理事件循环。

Workarounds

  1. 98% success 
    Install the plugin and enable auto mode:

pip install pytest-asyncio

# pytest.ini
[pytest]
asyncio_mode = auto
  2. 90% success 
    Use anyio instead:

pip install anyio

# test file
import pytest

@pytest.mark.anyio
async def test_thing():
    ...

Dead Ends

Common approaches that don't work:

  1. 90% fail

    The test function itself is still async, so pytest still rejects it during collection.

  2. 95% fail

    The setting is only read by pytest-asyncio; without the plugin installed the option is ignored and the error persists.