Install Allegro from Ubuntu PPAs
Allegro 5 has official Ubuntu PPAs. You can download recent releases of Allegro this way without needing to compile it yourself.
For the stable branch (5.2) run this command in your terminal:
sudo add-apt-repository ppa:allegro/5.2
Now, run these commands to install the development versions of Allegro:
sudo apt-get update sudo apt-get install liballegro5-dev