CDN: trunk URL couldn't be downl

pod install 时候遇到报错

[!] CDN: trunk Repo update failed - 113 error(s):

CDN: trunk URL couldn't be downloaded: https://cdn.jsdelivr.net/cocoa/Specs/1/1/7/SDWebImage/2.4/SDWebImage.podspec.json Response: Couldn't resolve host name

CDN: trunk URL couldn't be downloaded: https://cdn.jsdelivr.net/cocoa/Specs/1/1/7/SDWebImage/2.5/SDWebImage.podspec.json Response: Timeout was reached

CDN: trunk URL couldn't be downloaded: https://cdn.jsdelivr.net/cocoa/Specs/1/1/7/SDWebImage/2.7.4/SDWebImage.podspec.json Response: Couldn't connect to server

尝试解决问题：i

1.准备修改hosts

199.232.4.133  raw.githubusercontent.com

cd /etc

ls -a

rm -rf .hosts.swp //这个命令针对如果之前对host编辑却没有保存好数据的时候  同样在未保存界面编辑D删除也可以

sudo vim hosts 

输入i 进入编辑状态（insert状态，如下图）

按esc 输入 :qw 退出  (这个hosts的编辑十分难用，编辑完一定要再查看。而且每次如果不保存好就关掉的话也会出问题)

移除之前的trunk， 在podfile中添加source 'https://github.com/CocoaPods/Specs.git'

pod repo remove trunk

经过以上处理后重新pod  解决了。