PBR is a library that injects some useful and sensible default
behaviors into your setuptools run.

PBR is only mildly configurable. The basic idea is that there's a
decent way to run things and if you do, you should reap the rewards,
because then it's simple and repeatable. If you want to do things
differently, cool! But you've already got the power of python at your
fingertips, so you don't really need PBR.