darwin-configuration.nix

{ config, pkgs, ... }:

{
  imports = [ <home-manager/nix-darwin> ];

  # List packages installed in system profile. To search by name, run:
  # $ nix-env -qaP | grep wget
  environment.systemPackages = with pkgs; [ 
    wget
    curl
    tree
    git
    vim
  ];

  environment.shells = [ pkgs.fish ];

  # Use a custom configuration.nix location.
  # $ darwin-rebuild switch -I darwin-config=$HOME/.config/nixpkgs/darwin/configuration.nix
  environment.darwinConfig = "$HOME/.config/nixpkgs/darwin-configuration.nix";

  nixpkgs.overlays = [ (import /Users/tom/.config/nixpkgs/overlays/fish) ];

  # Auto upgrade nix package and the daemon service.
  services.nix-daemon.enable = true;
  # nix.package = pkgs.nix;

  # Create /etc/bashrc that loads the nix-darwin environment.
  programs.bash.enable = true;
  programs.fish.enable = true;
  programs.fish.shellInit = ''
      for p in /run/current-system/sw/bin
        if not contains $p $fish_user_paths
          set -g fish_user_paths $p $fish_user_paths
        end
      end
    '';

  # Used for backwards compatibility, please read the changelog before changing.
  # $ darwin-rebuild changelog
  system.stateVersion = 4;

  # You should generally set this to the total number of logical cores in your system.
  # $ sysctl -n hw.ncpu
  nix.maxJobs = 12;
  nix.buildCores = 12;

  home-manager = {
    useUserPackages = true;
    users.tom = import ./home.nix { inherit pkgs; };
  };
}

cat overlays/fish/default.nix
self: super:
{
  programs.fish = super.programs.fish.override {
   shellInit = ''
     for p in /run/current-system/sw/bin
       if not contains $p $fish_user_paths
         set -g fish_user_paths $p $fish_user_paths
       end
     end
   '';
  };
}