Install ruby from source

Download latest version of ruby source code from

https://www.ruby-lang.org/en/downloads/

At the time of writing this, latest version is 2.6.0

cd /usr/local/src
wget https://cache.ruby-lang.org/pub/ruby/2.6/ruby-2.6.0.tar.gz
tar -zxvf ruby-2.6.0.tar.gz
cd ruby-2.6.0
./configure
make
make install