cabal: question on compiling build prerequisites

[Henning Thielemann]

On Fri, 6 Dec 2013, Peter Selinger wrote:

> My current solution is to make the pre-processor a shell script,
> rather than a Haskell program. But this is ugly and not portable
> (won't work in Windows, for example).
>
> To clarify: my custom preprocessor is local to this package. It has no
> independent value, so it would not make sense to publish it as a
> separate package just so that I can add it to build-depends.
>
> Is there a known solution to this problem?

I have not tried this solution but I would guess that it is a good idea to 
put the preprocessor in a separate package anyway, since it might have its 
own build-depends.