I would like to have a GHC option like -fwarn-unqualified-imports that warns about those kinds of imports that require to have A.B.C.* constraints for PVP-compliant packages. Namely, GHC should warn about implicit unqualified imports like

import Very.Special.Module
import Another.Important.Module hiding (open, close, )

http://www.haskell.org/haskellwiki/Package_versioning_policy http://www.haskell.org/haskellwiki/Import_modules_properly http://www.reddit.com/r/haskell_proposals/comments/edu3f/discourage_unqualified_open_imports/