pod 报错sudo gem install -n /usr/l

Mac更新系统到macOS High Sierra后，pod install 出现下面提示：

-bash: /usr/local/bin/pod: /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby: bad interpreter: No such file or directory

之后经过查询得知，可以这样解决问题

sudo gem update --system
sudo gem install -n /usr/local/bin cocoapods