Hi, The Yhc compiler depends on an increasingly large number of Cabal packages - mtl and FilePath at the moment, but soon thats likely to increase by at least 3. Cabal is not yet mature enough to compile Yhc, and fitting in a compile of bits with Cabal will be quite hard because of the existing complexity in Scons. So what we'd really like to do is be able to call "cabal check-its-installed FilePath", which would return an appropriate exit code. If it wasn't installed then a darcs get, followed by a "cabal install-it-please" would be very handy. Does cabal-install provide the necessary bits for this? What is the result of installing a package that is already installed? How long til this kind of solution will be widely enough deployed that we can actually use it? Does anyone else have any other suggestions? Thanks Neil