$ git clone https://github.com/rbenv/rbenv.git ~/.rbenv
$ cd ~/.rbenv && src/configure && make -C src
$ git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
$ tail -2 .bashrc
export PATH=$HOME/.rbenv/bin:$PATH
eval "$(rbenv init -)"
$ rbenv install 2.4.1
そこから