Thanks, I'll give it a try, though I'm using Minitest. I haven't really tried much yet on that front; I mostly just got to the point of realizing that this issue I'm working on now is really going to be a pain to get figured out without a debugger.
For this project, I just switched, like a month or so ago, to an all-Vim workflow. I mostly feel more productive in it so far, but a real debugger is the one thing that I had been putting off figuring out.