I learned the very hard way that it is a very silly silly thing to work on the master branch of aosp.
Your will not be around for long as you search for days trying to find out how you broke something so you can fix it but alas you shall never be so lucky because you were not the one who broke it.

Time wasted learning that lesson: 37 hours
Caffiene consumed: 8 monsters and 6 liters of pepsi