Since the hat mailing list seems a bit unresponsive, (or I seem to be impatient), I'm forwarding the attached post here. I've also attached the Makefile that produced the error message shown in the attachment. When the Makefile target is run, it works. However, with target=hat, It produces the error shown in the forwarded msg: Hat/tickSimple.hs:4:0: Bad interface file: /usr/lib/haskell-packages/ghc6/lib/hat-2.05/ghc-6.8.2/Hat/Prelude.hi Something is amiss; requested module main:Prelude differs from name found in the interface file hat-2.5:Hat.Prelude Please, how should the Makefile be modified to avoid this error? -Hopefully, Larry MAIN=Insort MAIN=tickSimple INCS=/usr/lib/haskell-packages/ghc6/lib/hat-2.05/ghc-6.8.2/Hat GHC.FLAGS=-P$(INCS) GHC.LANG=-XMultiParamTypeClasses -XFunctionalDependencies -XFlexibleInstances GHC.OPTS=$(GHC.FLAGS) $(GHC.LANG) run: runghc $(GHC.LANG) $(MAIN).hs hat: hmake -hat $(GHC.OPTS) $(MAIN)