The Android build system is officially supported by Ubuntu Linux. Google assures that the system setup, the environment setup, and all the requirements are easily reproducible on this particular Linux distribution. The truth is, nowadays, every Linux distribution can be prepared to perform a proper Android build with little effort.
To be closest to the guidelines and because we think that Ubuntu is the easiest system to set up for the job, in this book we are going to use Ubuntu Linux 15.04 to perform all our building procedures.
If you are working on OS X or Windows and you prefer to stick to these operating systems, we are going to show you how to achieve our goal even using a virtual machine.
The amount of free space on the hard drive needed by the build system is massive. The Android source code by itself can reach 100 gigabytes of occupied space. When we move to more advanced scenarios, such as building using a caching system, such as ccache, to speed up multiple system builds, we can easily reach 200 gigabytes of occupied space. It's very important to be sure that this kind of free space is available on your machine, because filling up the hard disk during the building process could bring the system into an unstable state.
Another note is about your connection speed—considering the amount of data needed to get ready to build, be sure to have a fast Internet connection, or an appropriate amount of patience.