Debugging

[Thomas Bushnell, BSG]

I can't find out how to single step in the guile debugger, let alone
have it interface well with my emacs.  And what about breakpoints?

In addition, I want an emacs that will put a nice little arrow next to
the source when guile hits an error.  

I'm not sure if I'm using the wrong guile mode.  M-x run-scheme was
suggests; that gets me cmuscheme mode, which works a little.  If I
load xscheme, I seem to get something that badly blows chunks.