[!] Unable to add a source with

$ pod install

Analyzing dependencies
Cloning spec repo cocoapods from https://github.com/CocoaPods/Specs.git
[!] Unable to add a source with url https://github.com/CocoaPods/Specs.git named cocoapods.
You can try adding it manually in /Users/fanxianchao/.cocoapods/repos or via pod repo add.

• 解决：

更换国内的镜像, 清华的不错
$ cd ~/.cocoapods/repos 
$ pod repo remove master
$ git clone https://mirrors.tuna.tsinghua.edu.cn/git/CocoaPods/Specs.git master
然后记得去自己项目podfile里把source换了

source 'https://mirrors.tuna.tsinghua.edu.cn/git/CocoaPods/Specs.git'
再重新pod update

• 参考
  https://www.jianshu.com/p/4a118f93e6ed