> I've run into a couple of cases when attempting to support multiple GHC versions in my libraries (7.6.3 -> 7.10) where I've repeatedly made mistakes due to being warned about unused imports for various modules that are now part of the Prelude such as Data.Monoid, Data.Foldable, etc. which I subsequently remove either manually or via editor automation sufficiently indistinguishable from magic.

A trick is to import Prelude at the very end, like:

import Control.Applicative

import Data.Monoid
...

import Prelude

Since the unused import check is done from top to bottom, and you almost always use *something* from the Prelude, this will suppress the warning.

There are some problems with qualified/explicit import lists if I recall correctly though. But it works for me most of the time.

Regards,

Benno