Error installing sass:
ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
出现这种情况！怎么配置
1.首先看提示，提示说你最有可能的错误是少装了什么东西或文件，你重新看看是不是哪一步跳过去或者失败了。
2.可能要cross gwf，你要不改用淘宝或网易的镜像源。
3.看看mkmf.log里面的详细说明，或许能进一步找到问题的原因。
4.万能重装大法，删掉ruby下的cache文件，重新搞一遍。
一般都是万能重装大法，重新搞一遍。
sass是基于ruby语言开发的，所以需要先安装ruby,然后gem install sass安装sass.
具体可参考：https://www.sass.hk/install/ 这个里面讲的很详细。
执行命令sudo gem install sass,错误如下
current directory: /Users/apple/.rvm/rubies/ruby-2.4.1/lib/ruby/gems/2.4.0/gems/ffi-1.11.1/ext/ffi_c
/Users/apple/.rvm/rubies/ruby-2.4.1/bin/ruby -r ./siteconf20190929-8232-zxxp67.rb extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
解决方法:
1.命令行输入: rvm -v
提示: rvm 1.29.4 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
2.ruby -v
ruby 2.4.1p111 (2017-03-22 revision 58053)
3.rvm uninstall 2.4.1p111
ruby-2.4.1p111 - #already gone
4.rvm get stable
RVM reloaded!
5.rvm -v
rvm 1.29.9 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
6.sudo gem install sass
Fetching: sass-3.7.4.gem (100%)
7.sass -v
Ruby Sass 3.7.4