package08e.hs:2:1: Failed to load interface for ‘MyHsTypes’ Perhaps you meant HsTypes (needs flag -package-key ghc-) Use -v to see a list of the files searched for. package08e.hs:3:1: Failed to load interface for ‘HsTypes’ It is a member of the hidden package ‘ghc-’. Use -v to see a list of the files searched for. package08e.hs:4:1: Failed to load interface for ‘HsUtils’ It is a member of the hidden package ‘ghc-’. Use -v to see a list of the files searched for. package08e.hs:5:1: Failed to load interface for ‘UniqFM’ It is a member of the hidden package ‘ghc-’. Use -v to see a list of the files searched for.