Transforms-external-systems library installation failing

I am currently doing the Deep Dive: Creating your first Data Connection training course, and I get to the step where I need to add and install the external library (transforms-external-systems), and I keep getting the same build/installation error, which is inhibiting more from proceeding along with the course. Below is a snippet of the error that I am receiving when trying to install this library. Any advice? Thanks!

same problem, I haven’t come up with a solution yet.