WARNING in hptSomeThingsBelowUs

This is what I get after removing a file from the working tree and also from the cabal file for the project and then rebuild. WARNING in hptSomeThingsBelowUs missing module Darcs.Util.Environment Probable cause: out-of-date interface files I am using cabal new-build. Cabal folks tell me this is a ghc problem. I am using ghc-7.10.3. Cheers Ben