# 错误：无法安装 numpy==1.26.4 和 Cython>=3.0，因为这些包版本的依赖项存在冲突。
冲突由以下原因引起：
    用户请求 numpy==1.26.4
    Cython 3.0.10 依赖于 numpy>=2.0

- **ID:** `python/pip-build-deps-conflict-cython-numpy`
- **领域:** python
- **类别:** install_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

构建时依赖和运行时固定版本被混在同一个 requirements 文件中，产生了无法满足的依赖图。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 3.x | active | — | — |

## 解决方案

1. **** (92% 成功率)
   ```
   [build-system]
requires = ["setuptools>=68", "wheel", "Cython>=3.0", "numpy>=2.0"]
build-backend = "setuptools.build_meta"
# then
pip install .
   ```
2. **** (85% 成功率)
   ```
   echo 'numpy==1.26.4' > constraints.txt
pip install -c constraints.txt Cython>=3.0
   ```

## 无效尝试

- **** — Skips dependency installation entirely, leaving the environment broken at runtime. (80% 失败率)
- **** — Legacy resolver may install an inconsistent set silently, causing runtime errors. (70% 失败率)
- **** — May pull numpy 2.x, incompatible with other pinned packages in the project. (50% 失败率)