Installer nix. Par exemple, sous WSL:
[[https://github.com/nix-community/NixOS-WSL]] Puis modifier
/etc/nixos/configuration.nix.

** 1. Emacs nativecomp + flakes + WSL
:PROPERTIES:
:CUSTOM_ID: emacs-nativecomp-flakes-wsl
:END:
Il faut rajouter un overlay. Cela va compiler emacs

#+begin_src sh
{ lib, pkgs, config, modulesPath, ... }:

with lib;
let
  nixos-wsl = import ./nixos-wsl;
in
{
  imports = [
    "${modulesPath}/profiles/minimal.nix"

    nixos-wsl.nixosModules.wsl
  ];

  wsl = {
    enable = true;
    automountPath = "/mnt";
    defaultUser = "nixos";
    startMenuLaunchers = true;

    # Enable integration with Docker Desktop (needs to be installed)
    # docker.enable = true;
  };

  # Enable nix flakes
  nix.package = pkgs.nixFlakes;
  nix.extraOptions = ''
    experimental-features = nix-command flakes
  '';

  # Emacs28 with nativecomp
  services.emacs.package = pkgs.emacsNativeComp;

  nixpkgs.overlays = [
    (import (builtins.fetchTarball {
      url = https://github.com/nix-community/emacs-overlay/archive/master.tar.gz;
    }))
  ];

  environment.systemPackages = with pkgs; [
          emacsNativeComp
  ];
}
#+end_src

Puis installer avec

#+begin_example
nixos-rebuild switch
#+end_example

** 2. Ajouter des logiciels au niveau global
:PROPERTIES:
:CUSTOM_ID: ajouter-des-logiciels-au-niveau-global
:END:
il sufit de modifier

#+begin_example
environment.systemPackages
#+end_example

et de lancer ensuite

#+begin_src sh
nix-os rebuild switch
#+end_src

NB: il manque man par défaut !. Doc officielle :
[[https://nixos.org/manual/nixos/stable/]]

** Suivre avancement des branches (unrstable, stable...)
:PROPERTIES:
:CUSTOM_ID: suivre-avancement-des-branches-unrstable-stable
:END:
Plusieurs possibilités

1. [[https://nixpk.gs/pr-tracker.html?pr=188777]]
2. [[https://status.nixos.org/]]
3. Simply clicking on a commit on GitHub shows branches and tags
   containing that commit.