When I try to use it with SLIME on SBCL, it invokes the debugger in *inferior-lisp* instead of SWANK. I tried to figure it out before but couldn't, but what just popped into my head is that this could be due to different bindings for dynamic variables in Hunchentoot threads vs. the SWANK repl thread.
On another note, I don't like the debugging-acceptor code. What was wrong with http://paste.lisp.org/display/81046? That was much more straightforward.
Vladimir