Please add following line to your /etc/apt/sources.list file:
deb http://ubuntu.ada-language.com/14.04 ./
Once you have changed sources.list file, run following commands:
sudo apt-get update sudo apt-get install avr-ada
AVR-Ada package is not signed, so you need to answer Yes ('y') to tell apt-get that you really want to install unsigned package.
Tero Koskinen - 2014-06-02