今天要从 svn 上 checkout 一个新文件夹出来，结果意外发生了。
首先，控制台告诉我：
svn: error: The subversion command line tools are no longer provided by Xcode
查找资料知道可以通过 brew 安装来解决：
brew install subversion
然后事故紧接着又出现了：
Running Homebrew as root is extremely dangerous and no longer supported.
As Homebrew does not drop privileges on installation you would be giving all
build scripts full access to your system.
emm，ok，你对安全性要求高，你赢了。好在官方已经提供了解决方法：
mkdir homebrew && curl -L https://github.com/Homebrew/brew/tarball/master | tar xz --strip 1 -C homebrew
一波三折，心情无以言表。
