Hi, I made a little progress after crippling GHC.Fingerprint: The package at https://github.com/nomeata/packages-base/tree/base-pure (Branch base-pure) builds and contains just these modules: ./Control/Applicative.hs ./Control/Arrow.hs ./Control/Category.hs ./Control/Monad/Fix.hs ./Control/Monad.hs ./Data/Bits.hs ./Data/Bool.hs ./Data/Either.hs ./Data/Eq.hs ./Data/Foldable.hs ./Data/Function.hs ./Data/Functor.hs ./Data/Int.hs ./Data/List.hs ./Data/Maybe.hs ./Data/Monoid.hs ./Data/Ord.hs ./Data/Ratio.hs ./Data/Traversable.hs ./Data/Tuple.hs ./Data/Typeable.hs ./Data/Typeable.hs-boot ./Data/Typeable/Internal.hs ./Data/Typeable/Internal.hs-boot ./dist/build/autogen/Paths_base_pure.hs ./GHC/Base.lhs ./GHC/Char.hs ./GHC/Enum.lhs ./GHC/Err.lhs ./GHC/Err.lhs-boot ./GHC/Exception.lhs ./GHC/Fingerprint.hs ./GHC/Fingerprint/Type.hs ./GHC/Int.hs ./GHC/List.lhs ./GHC/Num.lhs ./GHC/Real.lhs ./GHC/Show.lhs ./GHC/Word.hs ./Prelude.hs (contains just $!) ./Unsafe/Coerce.hs The crippling can be seen here: https://github.com/nomeata/packages-base/blob/base-pure/GHC/Fingerprint.hs So if there were a magic way of getting a working GHC.Fingerprint module without pulling in Foreign, this would be a good start for a base free of any trace of * Foreign * IO * Floating point arithmetic * Read * ST * Array Alternative, a magic way of providing the functions error and divZeroError without having to define Exceptions would do well. I guess it is not possible to define the "data ErrorCall" without the Exception class and somehow call the primop raise# in a way that the error can be caught, as catch will expect something of type "SomeException" that has the Exception dictionary bundled. Any idea how to achieve that, without having resort to ghc-bottom as suggested by Ian (which would be ok, but not as nice as genuine small packages to start with)? Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata@debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata@joachim-breitner.de | http://people.debian.org/~nomeata