How can I get the position where error was called?

Question

I am looking for something to replace loch (and its preprocessor) since it doesn\'t compile with ghc 7.

Specifically, if error is called then I would l

Answer 1

You can use the -xc RTS option, as described on this page; you need to compile your program with profiling support, and the output is pretty ugly, but it works.

This should do it:

$ ghc --make -prof -auto-all myprog.hs
$ ./myprog +RTS -xc

Technically this only gives a cost centre stack, not a true stack trace. Improved stack trace support is coming in GHC 7.4.