Where is this functionality provided by Nix?
simply run these commands
...
# Haskell Platform 2012.2.0.0' nix-env -p ~/ghc-7.4.1 -iA haskellPackages_ghc741.haskellPlatform
and you'll have profiles that contain the appropriate binaries and
Hi Peter and Andres, libraries
defined by the corresponding platform.
What you have here is a mechanism for setting up a user-environment for an appropriate platform. Unfortunately I cannot see how it can address any of the user-level Haskell package database management and sandboxing mechanisms that I mentioned in the announcement and subsequent emails. Also it requires that the user load up a special environment before going to work on a work tree rather than the drivers detecting from the context the correct toolchain and invoking it automatically. It might not sound like much but imagine how it would be if you had to set up a special environment before you could work with a git work tree -- there is quite a difference between the two approaches in practice. Finally the Nix method is of course fundamentally dependent upon Nix. I can appreciate why you may believe that everybody should just get Haskell through Nix but I think there is merit to developing a mechanism that allows Haskell to be better packaged regardless of its distribution channel. If I thought there was any chance at all that Haskell could be universally provided through Nix then it might be different, but I don't. None of which detracts from general excellence of Nix and the Nix Haskell distribution. And I still think the mechanism I am proposing would work well with the Nix distribution. Indeed it may be best placed to make full use of it. Chris