Sometimes compilation fails because of unmet system dependencies, or compilation succeeds but the new Ruby version exhibits weird failures at runtime. The following instructions are our recommendations for a sane build environment:

sudo apt-get install autoconf bison build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev

You can install Ruby from source. Download and unpack a tarball, then just do this:

./configure
make
sudo make install

By default, this will install Ruby into /usr/local. To change, pass the –prefix=DIR option to the ./configure script.