Install gnat by running the following commands: ./doconfig The above script will ask you how and where you would like to install gnat. To avoid conflicts with the system gcc, the package will be installed in a separate directory, that can later be removed from the system. In response to the questions asked by the doconfig script, enter 3 in response to the first question and /opt/gnat in response to the second question. To finish the install, run ./doinstall The gnat compiler can be invoked by executing the gcc binary installed by the above script.