一些问题

一.更新 gem 的时候出错

ERROR: While executing gem ... \(Errno::EPERM\) Operation not permitted - \/usr\/bin\/update\_rubygems

 ```

1.安装 Homebrew 一个Mac上用于管理命令行软件的工具

 \/usr\/bin\/ruby -e "$\(curl -fsSL https:\/\/raw.githubusercontent.com\/Homebrew\/install\/master\/install\)"

2.安装ruby

 brew install ruby

3.更新至最细的gem

 sudo gem update --system

###  二.  "....with the Podfile.lock .."问题

diff: /../Podfile.lock: No such file or directory 
diff: Manifest.lock:No such file or directory 
error: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or   update your CocoaPods installation.`

 问题解决方法:

![problem.png](http://upload-images.jianshu.io/upload_images/707510-c7bc2f14c35c7bbd.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
### 三.不能获取最新的版本
$rm -fr ~/.cocoapods/repos/master$pod setup