[Haskell-beginners] finding the exact instance of a function causing an error

Hey, I have a program, that, when I run it fails with: Main: Prelude.tail: empty list Can I somehow find out which exat instance of tail causes this error? I tried compiling with -prof and running with +RTX -xc, which gives me: *** Exception (reporting due to +RTS -xc): (THUNK_2_0), stack trace: GHC.List.CAF --> evaluated by: SYSTEM.SYSTEM *** Exception (reporting due to +RTS -xc): (THUNK_2_0), stack trace: GHC.List.CAF *** Exception (reporting due to +RTS -xc): (THUNK_2_0), stack trace: GHC.List.CAF Does not really help me ... Thanks! Nathan