[Haskell-cafe] Best way to find an "undefined" error?

[Scott West]

Hello all,

Does anyone favourite technique to track down an "undefined" call? I'm
99% sure that my code is not the offender (I've grepped for undefined
occurrences and turned them all into "error" calls). Supposing that
this is happening in some other package or library that I'm using,
what is the best way to find out where it is? I have profiling enabled
on all libraries that I use, so I'm ok there I think. Any magic
combination of +RTS .. -RTS?

Scott