pip 安装 dnet 老是失败

[LINEX]

MAC OS 下命令：
sudo pip install dnet -i --trusted-host http://pypi.douban.com/simple
安装失败，提示我错误：
Cannot unpack file /private/tmp/pip-xtd2zY-unpack/simple (downloaded from /tmp/pip-Y8Yd-build, content-type: text/html; charset=utf-8 ); cannot detect archive format
Cannot determine archive format of /tmp/pip-Y8Yd-build

如何解决这个问题?