...instead of posting here, but I guess I can use a few minutes to briefly introduce the SoC project I am working on.
Haskell is a beautiful, lazy functional programming language, and GHC is its compiler. We (that's me and my headache) are working in a easy to use, simple, bare to the bones debugger based on GHC, or GHC-interactive to be more specific. How come there isn't a debugger for Haskell yet?
Well, of course there are debuggers, and they are far more advanced than the one we are aiming at. See for instance the Hat tracer. The main problem is that they are outdated, since they cannot keep up with the evolutional speed of Haskell. Haskell 98 is the standard, but every new version of GHC sets the current status of the language, implementing several (lots of) experimental extensions. Haskell research community is enormously active.
As a result, you are restricted to a (bigger or smaller) subset of the language if you want to use one of these debuggers. Our goal is to build on top of the very own GHC machinery so that our debugger will never restrict you or get outdated. And to keep it simple.
Wish us good luck :)
(ok, I swear the jokes about my headache end here)
PS: Just to clarify, the debugger is not to my credit. I am only doing on a tiny part, building on top of the work of David Himmelstrup, my mentor (poor soul).