Update: I was able to avoid the seg fault. I think the issues was, one of the terminals I had was a point, instead of a line or rectangle. After fixing this, magic stopped crashing. However, the issue I have now is that the router always gives this error once per terminal:

Feedback #1: No crossing reachable from terminal

I am trying to follow along Tutorial 7 and this same issue appears when I try to route tut7d.mag.