1. The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.
解决方法：根据提示重新pod install
2.
CocoaPods could not find compatible versions for pod "ZLCategory":
In snapshot (Podfile.lock):
ZLCategory (= 0.1.1)
In Podfile:
ZLCategory
None of your spec sources contain a spec satisfying the dependencies: `ZLCategory, ZLCategory (= 0.1.1)`.
You have either:
* out-of-date source repos which you can update with `pod repo update` or with `pod install --repo-update`.
* mistyped the name or version.
* not added the source repo that hosts the Podspec to your Podfile.
Note: as of CocoaPods 1.0, `pod repo update` does not happen on `pod install` by default
使用pod update命令
3.
/Users/zhaoliangchen/Desktop/anxin/Pods/Pods/Target Support Files/Pods-anxin/Pods-anxin.debug.xcconfig: unable to open file (in target "anxin" in project "anxin") (in target 'anxin')
解决方法：
选择正确的路径
4. pod update时候显示详细信息,并跳过Updating spec repo `master`
pod update --verbose --no-repo-update
5. pod update 的时候 Cloning into 'master' 速度慢
使用清华镜像
https://mirror.tuna.tsinghua.edu.cn/help/CocoaPods/
$ cd~/.cocoapods/repos
$ pod repo remove master
//清华的镜像
$ git clone https://mirrors.tuna.tsinghua.edu.cn/git/CocoaPods/Specs.git master
//coding的镜像
$ git clone https://git.coding.net/hging/Specs.git master
最后进入自己的工程，在自己工程的podFile第一行加上：
source 'https://mirrors.tuna.tsinghua.edu.cn/git/CocoaPods/Specs.git'
6. 取消代理
终端输入 git config --global --unset http.proxy
取消代理.
7. curl 56 LibreSSL SSL_read: SSL_ERROR_SYSCALL, errno 54
rm-rf~/Library/Caches/CocoaPods/
pod repo update
