which is determining the abspath of $PWD/..
A more reliable way to determine the rootdir is relative to the dirname(__file__) of the python module itself.
There's actually a fix for this already in review, by either bkhudson or dstanek.
I'd like to see more justification before approving for stable, this bug is set as Low and it doesn't describe in which situation/setup it shows up?
My reasoning for the Low priority is that it only affects test execution rather than the core functionality of the project. The root directory will be incorrectly determined if the working directory happens to not be in keystone/ -- making the tests a bit fragile. Basing directory resolution on __file__ makes it completely unambiguous.