That command looks correct. You don’t have to “…” all the way back out of the RSB. I regularly use something similar to that command shown when in the rtems/ directory – just the one level “up and over” shown there.
I am guessing from the top of the rsb and in the rtems/ directory manage to find the Python support files. Not finding them is giving the odd behavior you see.
@kiwichris Am I on the right path with the failure explanation?