ghc-Stack-Clean.tgz
-------------------
(14th June, 2010)

Contains a ghc source tree with the stack trace patches applied.

The source tree was a GHC head just before ghc 6.12 came out - the prototype
patches no longer apply cleanly to an up-to-date-ghc due to ghc's fast moving
codebase (and updated build system).  Because it's a pre 6.12 codebase, this
source has to be built with a version of GHC pre 6.12. (ghc-pkg changed output
format).  

***
i.e.: configure and build with something like:

  $ ./configure --with-ghc=ghc-6.10.1 && make

***

If you don't want to make-install, you can run ghc from its in-place location:

$ ~/ghc-Stack-Clean/ghc/stage2-inplace/ghc -fds-simple -fexplicit-call-stack-all --make Foo


For reference, a full example showing a suitable definition for an error' function that can get at the stack.

$ cat Foo.hs

  module Main where

  import Control.Exception
  import GHC.ExplicitCallStack.Stack

  foo0, foo1, foo2, foo3, foo4 :: Bool -> ()

  foo0 x = foo1 x
  foo1 x = foo2 x
  foo2 x = foo3 x
  foo3 x = foo4 x
  foo4 False = foo0 True `seq` error' "Ouch!"
  foo4 True  = ()

  main :: IO ()
  main = print $ foo0 False

  error' :: String -> a
  error' msg = throwStack (\s -> ErrorCall (msg ++ "\n" ++ (show s)))