Emacs: add tree-stitter support

This reverts commit 069072653a.

flake.lock

@@ -33,6 +33,29 @@
         "type": "github"
       }
     },
+    "emacs-overlay": {
+      "inputs": {
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "nixpkgs": [
+          "nixpkgs-unstable"
+        ]
+      },
+      "locked": {
+        "lastModified": 1685293468,
+        "narHash": "sha256-weksQQ0YGFk6pjW4Ms5eC1HURH8otWjIb8lJhkvKkZE=",
+        "owner": "nix-community",
+        "repo": "emacs-overlay",
+        "rev": "8b10f751e48ae0e48b3f037a352c7447dc7d1afe",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "emacs-overlay",
+        "type": "github"
+      }
+    },
     "fenix": {
       "inputs": {
         "nixpkgs": [
@@ -184,11 +207,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1685043448,
-        "narHash": "sha256-U3BwyDc2OzBcZ8tD09qXibyivgOtOQFTFCVgFyJ+6MM=",
+        "lastModified": 1685215858,
+        "narHash": "sha256-IRMFoDXA6cYx3ifVw3B2JcC4JrjT5v7tRAx2vro2Ffs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9886352ec9ab3945896ee8a4185e961fe29df209",
+        "rev": "ba6e4ddeb3e8ad3f3e3bec63dafbc9fe558729bb",
         "type": "github"
       },
       "original": {
@@ -279,6 +302,7 @@
     },
     "root": {
       "inputs": {
+        "emacs-overlay": "emacs-overlay",
         "fenix": "fenix",
         "flake-utils": "flake-utils",
         "lanzaboote": "lanzaboote",

flake.nix

@@ -36,10 +36,19 @@
         flake-utils.follows = "flake-utils";
       };
     };
+
+    emacs-overlay = {
+      url = "github:nix-community/emacs-overlay";
+      inputs = {
+        nixpkgs.follows = "nixpkgs-unstable";
+        flake-utils.follows = "flake-utils";
+      };
+    };
   };
 
   outputs =
     inputs@{ self
+    , emacs-overlay
     , fenix
     , flake-utils
     , lanzaboote
@@ -79,6 +88,7 @@
             ./modules/basic-tools
             ./modules/binary-caches.nix
             ./modules/devtools.nix
+            ./modules/emacs.nix
             ./modules/gnome.nix
             ./modules/gnupg.nix
             ./modules/mail

modules/emacs.nix

@@ -12,7 +12,14 @@
   services.emacs = {
     install = true;
     enable = false;
-    package = with pkgs; ((emacsPackagesFor emacsPgtk).emacsWithPackages (epkgs: with epkgs; [
+    package = with pkgs; ((emacsPackagesFor (emacsPgtk.overrideAttrs (old: {
+      passthru = old.passthru // {
+        treeSitter = true;
+      };
+    }))).emacsWithPackages (epkgs: with epkgs; [
+      # treesitter bits
+      treesit-grammars.with-all-grammars
+
       vterm
       pdf-tools
     ]));