Add emacs-overlay

nixos/dustbowl.nix

@@ -2,6 +2,7 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
+{ emacs-overlay }:
 { config, pkgs, ... }:
 
 {
@@ -131,7 +132,7 @@
     mako
 
     # GUI software
-    emacs
+    emacsPgtk
     firefox
     thunderbird
     mpv
@@ -163,18 +164,14 @@
   programs.steam.enable = true;
 
   nixpkgs.config.packageOverrides = pkgs: rec {
-    # Override emacs
-    emacs = pkgs.emacs.override {
-      withGTK3 = true;
-      withGTK2 = false;
-    };
-
     # Override firefox
     firefox = pkgs.firefox.override {
       forceWayland = true;
     };
   };
 
+  nixpkgs.overlays = [ emacs-overlay.overlay ];
+
   # Open ports in the firewall.
   networking.firewall.allowedTCPPorts = [ 8080 ];
   networking.firewall.allowedUDPPorts = [ 8080 ];