flake.lock: Update

Flake lock file updates:

• Updated input 'emacs-overlay':
    'github:nix-community/emacs-overlay/add5c977ba4e6a78d00b8f25277809e2301a5c29' (2023-03-21)
  → 'github:nix-community/emacs-overlay/e0bec9f768c938411adbc3861ae712cf38bf5a0a' (2023-03-23)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/eac7da7b519a5aefe92c33c90b4450a24ebe0ab3' (2023-03-19)
  → 'github:NixOS/nixpkgs/9ef6e7727f4c31507627815d4f8679c5841efb00' (2023-03-22)
• Updated input 'nixpkgs-unstable':
    'github:NixOS/nixpkgs/60c1d71f2ba4c80178ec84523c2ca0801522e0a6' (2023-03-19)
  → 'github:NixOS/nixpkgs/19cf008bb18e47b6e3b4e16e32a9a4bdd4b45f7e' (2023-03-21)

flake.lock

@@ -71,11 +71,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1679389595,
-        "narHash": "sha256-FEMLDJWfPszmdCu+uomkhTxlOqAL3dFl9y2RBbobF54=",
+        "lastModified": 1679540305,
+        "narHash": "sha256-W+9askXWmuEl2eKPvMG61ZpuygAWW0Unw7bbpja2Rsw=",
         "owner": "nix-community",
         "repo": "emacs-overlay",
-        "rev": "add5c977ba4e6a78d00b8f25277809e2301a5c29",
+        "rev": "e0bec9f768c938411adbc3861ae712cf38bf5a0a",
         "type": "github"
       },
       "original": {
@@ -308,11 +308,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1679262748,
-        "narHash": "sha256-DQCrrAFrkxijC6haUzOC5ZoFqpcv/tg2WxnyW3np1Cc=",
+        "lastModified": 1679437018,
+        "narHash": "sha256-vOuiDPLHSEo/7NkiWtxpHpHgoXoNmrm+wkXZ6a072Fc=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "60c1d71f2ba4c80178ec84523c2ca0801522e0a6",
+        "rev": "19cf008bb18e47b6e3b4e16e32a9a4bdd4b45f7e",
         "type": "github"
       },
       "original": {
@@ -324,11 +324,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1679224734,
-        "narHash": "sha256-1Ab3xY7Wgo1h1TNwRt6fp2XjV+KUo+hP1Bolh0KiDJs=",
+        "lastModified": 1679472241,
+        "narHash": "sha256-VK2YDic2NjPvfsuneJCLIrWS38qUfoW8rLLimx0rWXA=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "eac7da7b519a5aefe92c33c90b4450a24ebe0ab3",
+        "rev": "9ef6e7727f4c31507627815d4f8679c5841efb00",
         "type": "github"
       },
       "original": {

modules/nix-index-db.nix

@@ -30,7 +30,7 @@ with lib; {
             IOSchedulingClass = "idle";
             ExecStartPre = [
               "+${pkgs.coreutils}/bin/mkdir -p /var/db/nix-index/"
-              "+${pkgs.coreutils}/bin/chown nobody:nobody /var/db/nix-index/"
+              "+${pkgs.coreutils}/bin/chown nobody:nogroup /var/db/nix-index/"
             ];
             ExecStart = toString nix-index-db-update;
             User = "nobody";