Proposal: http://hackage.haskell.org/trac/ghc/ticket/1566 Currently, unix:System.Posix.Error has a number of throwErrnoPath* functions which are entirely portable, but they are not available on Windows due to being in the unix package. In the thread beginning http://www.haskell.org/pipermail/libraries/2007-July/007793.html Simon Marlow writes: When I needed to add some error-related functionality for the POSIX library, I didn't want to add extra stuff to Foreign.C.Error beyond what was specified in the FFI spec, so I added System.Posix.Error instead. This was just conservative; we could probably add throwErrnoPath and friends to Foreign.C.Error (with the usual proposal process). I propose that these functions are moved to base:Foreign.C.Error. They would still be re-exported by unix:System.Posix.Error to minimise breakage. Suggested deadline: Sun 12 August 2007. Thanks Ian