2023-05-27
Background: I use Nix Flakes and Home-Manager to manage my dotfiles and packages.
After witnessing the power of Nix, I recently made the switch to NixOS along with a neat Nix- based tool called home-manager, which allows you to manage your user profile declaratively. It was around this time that I was also trying out the Helix text editor. When I looked up the Helix package on search.nixos.org, I discovered that it was a version behind the latest release. Fortunately, nixos-unstable had the latest version available (23.05 at the time of writing this). Below is how I figured out how to use the unstable repository to install Helix.
Firstly, flake.nix allows you to define multiple inputs using:
inputs = {
nixpkgs.url = "github:nixos/nixpkgs/nixos-22.11";
# the unstable package repository
nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
home-manager = {
url = "github:nix-community/home-manager";
inputs.nixpkgs.follows = "nixpkgs";
};
};
Over in the output block, using the extraSpecialArgs parameter, I can pass in the unstable-pkgs to home manager.
outputs = { self, nixpkgs, nixpkgs-unstable, home-manager, ... }:
let
system = "x86_64-linux";
pkgs = nixpkgs.legacyPackages.${system};
unstable-pkgs = nixpkgs-unstable.legacyPackages.${system};
in
{
homeManagerConfigurations = {
<username> = home-manager.lib.homeManagerConfiguration {
inherit pkgs;
modules = [ ./home.nix ];
extraSpecialArgs = {
inherit unstable-pkgs;
};
};
};
};
Finally, in home.nix, I can reference the unstable-pkgs to download Helix from nixos-unstable.
# home.nix
{ config, pkgs, unstable-pkgs, ... }:
{
home.packages = [
unstable-pkgs.helix # installing from unstable repository
pkgs.alacritty # installing from stable repository
];
}