系統升級到最新版本（10.13.x）之後發現cocoapods更新失敗了，重新安裝之後也提示如下錯誤：
$ pod setup
-bash: /usr/local/bin/pod: /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby: bad interpreter: No such file or directory
複製程式碼說明pod的路徑沒有指向usr/local/bin目錄，所以只要更改一下install命令引數就好：
$ sudo gem install -n /usr/local/bin cocoapods
Successfully installed cocoapods-1.3.1
Parsing documentation for cocoapods-1.3.1
Done installing documentation for cocoapods after 2 seconds
1 gem installed
複製程式碼