ghc 6.0.1 win98 System.system too successful?

[Claus Reinke]

Shouldn't this return something other than ExitSuccess, occasionally?
Cheers,
Claus

PS. the first error message says "command not found"
PPS. this is from within cygwin's bash

$ ghci
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 6.0.1, for Haskell 98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base ... linking ... done.
Prelude>
Prelude> System.system "fail" >>= print
Befehl oder Dateiname nicht gefunden.
ExitSuccess
Prelude> System.system "diff ClassIn1.hs ClassIn1_TokOut.hs" >>= print
7c7
< class Reversable a where
---
> class MyReversable a where
11c11
< instance Reversable [a] where
---
> instance MyReversable [a] where
ExitSuccess
Prelude>