On Jan 14, 2007, at 18:53 , Neil Mitchell wrote:
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?
I think that cabal-install can do what you want already (except the darcs get, it downloads a tarball from Hackage instead). Give it a try and report any problems. /Björn