# UsageError: provided markers not found in collection: ['slow']

- **ID:** `python/pytest-marker-expression-error`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

使用 -m 参数指定标记，但测试中没有定义该标记

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 7.4.0 | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   在 pytest.ini 中添加 markers = slow: 慢速测试
   ```
2. **** (80% success)
   ```
   pytest --markers 列出所有可用标记
   ```

## Dead Ends

- **** — 如果标记未注册，pytest 仍会警告 (30% fail)
- **** — 导致没有测试运行 (90% fail)