CDN: trunk Repo update failed

今天在使用pod install时，出现了如下报错：
[!] CDN: trunk Repo update failed - 61 error(s):

解决办法：

1. podfile文件中指定source源为master：

source 'https://github.com/CocoaPods/Specs.git'

2.执行pod repo remove trunk移除trunk源

1.查看list
pod repo list

master
- Type: git (master)
- URL:  https://github.com/CocoaPods/Specs.git
- Path: /Users/zsq/.cocoapods/repos/master

trunk
- Type: CDN
- URL:  https://cdn.cocoapods.org/
- Path: /Users/zsq/.cocoapods/repos/trunk

2 repos
2. 移除trunk
pod repo remove trunk
Removing spec repo `trunk`