config.nix

{ pkgs }:

{
  allowBroken = true;
  allowUnfree = true;

  haskellPackageOverrides = with pkgs.haskell.lib; self: super: {

    # # Example of how to override a package attribute. (Note,
    # # however, that there's a much easier way to change this
    # # particular attribte in pkgs.haskell.lib, so this is for
    # # illustration only.)
    #
    # lens = overrideCabal (super.lens.overrideScope (self: super: {
    #   mkDerivation = drv: super.mkDerivation (drv // { enableLibraryProfiling = true; });
    # })) (drv: {});

    # Example of how to override a test failure with a local .nix file
    # libpq test in opaleye requirest a local Postgresql server
    #opaleye = dontCheck (self.callPackage ./opaleye.nix {});

    # Example of how to override a test failure using the standard Nix
    # config for that package.
    #zip-archive = dontCheck super.zip-archive;

    # Example of how to add your own package/override a package with a
    # local .nix file.
    # ghc-mod = self.callPackage ./ghc-mod.nix {};
    
  };

  packageOverrides = super: let self = super.pkgs; in with self; rec {

    # Required for OS X 10.11.
    llvmPackages = recurseIntoAttrs llvmPackages_37;

    # Override the emacs used in any expression.
    emacs = emacs24Macport;

    shell-env = buildEnv {
      name = "shell-env";
      paths = [
        ansible
        gitAndTools.git-crypt
        #keybase
        mediainfo
        pwgen
        speedtest-cli
        stow
        terminal-notifier
        tree
        unrar
        wakelan
        wget
        xz
        cabal2nix
      ];
    };

    emacs-env = buildEnv {
      name = "emacs-env";
      paths = with emacsPackagesNgGen emacs; [
         emacs
         aspell
         aspellDicts.en
      ];
    };

    python-env = python.buildEnv.override {
      extraLibs = with pythonPackages; [ virtualenvwrapper ];
    };

    haskellEnv = haskellPackages.ghcWithPackages (p: with p; [
      cabal-install
      hi
      hindent
      structured-haskell-mode
      stylish-haskell
    ]);

    # Local packages.

    # No longer used, but left as an example.
    #git-crypt = callPackage ./git-crypt.nix { };
  };
}