That's exactly why I never used Jekyll and don't really understand people that use it nowadays. It is AWFUL. Not only it uses greatly outdated Ruby, you also HAVE to install outdated Ruby on your machine to play with themes, serve, compile and are forced to use RVM. I know GitHub Pages can compile the page for you, but when you want to customize a theme you have to go through all that hell. It's just a terrible experience. And installing plugins is another hell.
I use Jekyll for a few sites and it works perfectly. Design is bootstrap and so nothing to do with Jekyll and it always compiles the site, takes a few seconds. Works fine on my mac and linux.
Would I have picked Jekyll today? no. Is it worth the cost of switching? no.
