pip 报错from versions: 问题

pip升级到6\7版本后，使用自搭建mirror的报错问题

pip_pypy install Flask
You are using pip version 7.0.1, however version 7.1.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting Flask
  The repository located at mirrors.zol.com.cn is not a trusted or secure host and is being ignored. If this repository is available via HTTPS it is recommended to use HTTPS instead, otherwise you may silence this warning and allow it anyways with '--trusted-host mirrors.zol.com.cn'.
  Could not find a version that satisfies the requirement Flask (from versions: )
No matching distribution found for Flask

主要是这句：
Could not find a version that satisfies the requirement Flask (from versions: )
No matching distribution found for Flask

困扰了好久，google也不到答案。

其实这样使用就可以了：

pip_pypy --trusted-host mirrors.zol.com.cn install Flask