安装sass前需安装ruby
安装好ruby好打开命令行，输入
1 gem install sass
出现错误：
1 ERROR: Could not find a valid gem 'sass' (>= 0), here is why: 2 Unable to download data from https://rubygems.org/ - SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (https://api.rubygems.org/specs.4.8.gz)
网上的解决方案是换成国内镜像https://ruby.taobao.org
代码：
1 gem sources --add https://ruby.taobao.org
然而试了一下发现还是报错：
1 Error fetching https://ruby.taobao.org/: 2 SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (https://rubygems-china.oss-cn-hangzhou.aliyuncs.com/specs.4.8.gz)
去stackoverflow上搜索了一番，发现可以这样：
1 gem sources --add http://rubygems.org
会提示：
1 https://rubygems.org is recommended for security over http://rubygems.org/
忽略，现在再试试gem install sass, 成功：
1 Fetching: sass-3.4.22.gem (100%) 2 Successfully installed sass-3.4.22 3 Parsing documentation for sass-3.4.22 4 Installing ri documentation for sass-3.4.22 5 Done installing documentation for sass after 18 seconds 6 1 gem installed
原文链接：https://www.jianshu.com/p/968697eb42eb