[Haskell-cafe] debugging <<loop>> exception

I'm getting Exception: <<loop>>. It doesn't print the line number. When I load the program into ghci, it still doesn't print the line number. When I trace the program in ghci it never gets to the point of emitting the exception. I set up my program in stack. I tried both "stack ghci" and just "ghci".. the latter to make sure it wasn't using any compiled code (at least in my own code). If it doesn't print a line number does this mean it's happening in compiled code? Any ideas how I can go about debugging this?