Cabal-dev is now capable of launching ghci with the project's package database and local modules (if the package under development exposes a library). For example: # First, invoke cabal-dev install the package to populate the # package database: $ cabal-dev install .... <snip> .... $ cabal-dev ghci GHCi, version 6.12.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package ffi-1.0 ... linking ... done. Prelude> The ghci shell should have access to all the libraries your application/library is using, as well as any modules that your library exposes. Note that this is not quite as natural as your traditional ghci shell, namely: Source modifications are not visible without exiting, re-issuing `cabal-dev install` *and* `cabal-dev ghci`. This will eventually get better, but that's where things are right now. The reason for this is that `cabal-dev ghci` just issues ghci with the cabal-dev package database (and excluding the user package db, to best reflect what cabal-dev does when it causes compilation). Cabal-dev is available on hackage and github: - http://hackage.haskell.org/package/cabal-dev - https://github.com/creswick/cabal-dev There is a short write-up with a (slightly) longer example here: - http://blog.ciscavate.org/2010/12/cabal-dev-sandboxing-your-haskell-developm... --Rogan