where does haskell packages in nixpkgs go?

Question

I once used nix-env -qaP <haskell-package-name> to search for a haskell package. But since I updated my nix channel some time ago, all haskell packages gone.

To be specific: qs@BF:~$ nix-channel --list nixpkgs https://nixos.org/channels/nixpkgs-unstable

qs@BF:~$ nix-env --version nix-env (Nix) 1.9

qs@BF:~$ uname -a Linux BF 3.13.0-35-generic #62-Ubuntu SMP Fri Aug 15 01:58:42 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

I wonder if I need to add some other channels which may contain haskell packages. Is there any thing to do with Haskell NG?

Thanks.

Answer 1

I remember seeing in the mailing list (although I cannot find the exact link now) from Peter Simons that the searching has been disabled through nix-env for Haskell packages from the top-level namespace since they are very big and nix-env was already quite slow. Instead all haskell packages are in a separate namespace named haskellPackages. For more information, see here. To install a Haskell package like text, you can use this command:

nix-env -i -A nixpkgs.haskellPackages.text

To find a package name, use this command:

nix-env -f "<nixpkgs>" -qaP -A haskellPackages | grep text