[racket] how do you raise a runtime error with source location information?

On Mon, Jun 20, 2011 at 10:00 PM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> I don't know if there is one already that is a good match for what you
> want, but you can always use prop:exn:srclocs to make a new one.

Feels like "Adding New Exception Types" oughta have its own section
immediately following "9.2.4 	Built-in Exception Types", starting with
the srclocs info.