NOTE: This project vendors a bunch of headers from Mesos 0.14.0 to prevent having to build both projects in parallel. It is not-unlikely to break against newer versions without reimporting these headers.
First, make sure libmesos.so (libmesos-0.14.0.so) is somewhere on your lib path.
gem build mesos.gemspec
gem install mesos-*.gem
Have a look at the files under examples.