How to include autoprefixer for Jekyll

I am able to use it with jekyll 3 by installing the octopress autoprefixer here: https://github.com/octopress/autoprefixer.

You then put: gems: [octopress-autoprefixer] in your config file. I am not using octopress, I only installed this to see if it would work.

In the process I also installed node.js (on a pc , win 10), so I could install autoprefixer-rails. Not sure if the octopress installer took care of this or not though, I was just trying random things to see if it would work. I think node.js was a requirement as I remember nothing happened until I rebooted and then everything worked.

It works great, though it does slow my build time down - on a small site that normally builds in .5 seconds it goes up to 12 seconds.