# OSError: [Errno 98] 地址已被占用
  在 tests/test_http.py::test_fetch 的设置期间
  端口 8080 已被占用

- **ID:** `python/pytest-httpserver-port-in-use`
- **领域:** python
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

之前的测试运行或其他进程仍占用该端口。在使用 pytest-httpserver、responses 或在 session 作用域 fixture 中启动但未拆除的本地开发服务器时很常见。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.0 | active | — | — |

## 解决方案

1. **** (97% 成功率)
   ```
   from pytest_httpserver import HTTPServer

def test_fetch(httpserver: HTTPServer):
    httpserver.expect_request('/api').respond_with_json({'ok': True})
    url = httpserver.url_for('/api')  # uses assigned port
    assert fetch(url) == {'ok': True}
   ```
2. **** (95% 成功率)
   ```
   @pytest.fixture(scope='session')
def server():
    srv = HTTPServer()
    srv.start()
    yield srv
    srv.stop()  # critical
   ```

## 无效尝试

- **** — Next run someone else uses 8081; whack-a-mole with no root fix and CI containers may have different free ports. (80% 失败率)
- **** — The port stays bound between retries; retries fail immediately. (90% 失败率)