[Nix-dev] Haskell packages installation

[Peter Simons]

Hi Sergey,

 > where can I find this ghc-wrapper ?

there are many versions of ghc-wrapper, one for every version of GHC
that we support:

  $ nix-env -qaP \* | grep ghc-.*-wrapper
  haskellPackages_ghc6104.ghc                ghc-6.10.4-wrapper
  haskellPackages_ghc6123.ghc                ghc-6.12.3-wrapper
  haskellPackages_ghc704.ghc                 ghc-7.0.4-wrapper
  haskellPackages_ghc741_no_profiling.ghc    ghc-7.4.1-wrapper
  haskellPackages.ghc                        ghc-7.4.1-wrapper
  haskellPackages_ghc741_profiling.ghc       ghc-7.4.1-wrapper
  haskellPackages_ghc742.ghc                 ghc-7.4.2-wrapper

The current default version is GHC 7.4.1, so you can install that one
simply by running "nix-env -i ghc".

Other versions can be selected by giving the full name, "nix-env -i
ghc-6.10.4-wrapper", or by using the attribute path (which is what I
personally prefer):

 $ nix-env -iA haskellPackages.ghc

In short, if you want to use the Haskell 'split' library via Nix, you
have to run

 $ nix-env -iA haskellPackages.ghc haskellPackages.split

or

 $ nix-env -i ghc-7.4.1-wrapper haskell-split-ghc7.4.1

Take care,
Peter