Tensorflow源码安装 GIT_DISCOVERY_ACROSS_FILESYSTEM not set, didn't match any files known to git解决

白天git clone 下载tensorflow安装包时候网速很慢经常失败，因此可以直接在网站下载tensorflow-master.zip,解压后如果直接源码安装会出现 GIT_DISCOVERY_ACROSS_FILESYSTEM not set, fatal: You are on a branch yet to be born， didn't match any files known to git 等错误，解决方案：

解压后

cd tensorflow

git init

git remote add origin https://github.com/tensorflow/tensorflow

git fetch

经过一段时间

git checkout r1.6

显示：

swiched to a new branch r1.6

搞定