> >         Call the original haddockHook with the updated flags rather
> >         than the
> >         haddock command.

main = defaultMainWithHooks simpleUserHooks {
 haddockHook = \pkg lbi h f ->

   let progs = userSpecifyArgs "haddock" ["--optghc=-D__HADDOCK__"]
                 (withPrograms lbi)
    in haddockHook simpleUserHooks pkg lbi { withPrograms = progs } h f
}