Bad error message for FFI declaration with no -fffi flag

[tim]

If I compile:

module Ccall where

import Foreign.C.Types

foreign import ccall "stdio.h putchar"
    putchar :: CInt -> IO CInt

I get:

$ ghc-6.8.1 -c -fext-core Ccall.hs  -no-recomp

Ccall.hs:5:8: parse error on input `import'

A better error message would be to suggest passing the -fffi flag.

[monoidal]

It is true that the error is really unhelpful, but now FFI is on by default as a part of the Haskell 2010 standard. I think the ticket is not worth implementing, then.