安装sass
gem install sass
出现了一个错误
ERROR:  While executing gem ... (Gem::FilePermissionError)
    You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory.

解决方法
sudo gem install sass --pre

安装sass
gem install sass
出现了一个错误
ERROR:  While executing gem ... (Gem::FilePermissionError)
    You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory.

解决方法
sudo gem install sass --pre