"Included in this revision is an experiment to see if the built-in 'rotate_extrude' could do a better job of things. Although it does play nicely with the CSG operations while viewing, it does not generate 2-manifold structures (and thus, no .stl files). I'm thinking maybe I need to overlap surfaces or something, rather than calculating exact vertices."
So... Maybe try the previous version, via the "derived from" link? Or disable this behavior if its an option?