overlays/emacs28: init

It was removed, but I need it for PLFA :c

nix/configurations/vanadium.nix

@@ -42,8 +42,9 @@ in
             disko
             nur
             wired-notify
-            packages
+            emacs28 # removed, but I need it for PLFA!
 
+            packages
             (import ./vanadium/nixos/overlay.nix)
           ];
 

nix/configurations/vanadium/home/programs.nix

@@ -54,7 +54,10 @@ in {
         neovim.enable = true;
         neovim.defaultEditor = true;
 
-        emacs.enable = true;
+        emacs = {
+          enable = true;
+          package = pkgs.emacs28;
+        };
 
         fish.enable = true;
         starship.enable = true;

nix/overlays/by-name/emacs28/overlay.nix

@@ -0,0 +1,8 @@
+{sources}:
+#
+_: _: {
+  emacs28 = let
+    pkgs = import sources.pin-emacs28 {};
+  in
+    pkgs.emacs;
+}

nix/sources.json

@@ -133,6 +133,18 @@
         "url": "https://github.com/nix-community/nur/archive/6b8339ef517be0618224555960e1693156de1bf9.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
+    "pin-emacs28": {
+        "branch": "master",
+        "description": "Nix Packages collection & NixOS",
+        "homepage": "",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "93c121f6888986f9148a33afd39d714f4b2ca98c",
+        "sha256": "198p4lv3zqw3s6j3yflgic0jxig4y0vsb1k8433jv227ks89kqdg",
+        "type": "tarball",
+        "url": "https://github.com/nixos/nixpkgs/archive/93c121f6888986f9148a33afd39d714f4b2ca98c.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "pin-fourmolu": {
         "branch": "haskell-updates",
         "description": "Nix Packages collection & NixOS",