Use 23.11 as default nixpkgs

flake.lock

@@ -70,16 +70,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1700854570,
-        "narHash": "sha256-GiwMS5sWSgF/CyZYbm+G5EcgG1VOEyvcsP5lE1L97Aw=",
+        "lastModified": 1701592216,
+        "narHash": "sha256-OVEAu1YBi3i8eB2f5uxR0Yws/uXgj2yHj/I963e6jxU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "cbd3f3722ac41a200c1655141e021cf12c3ba4e6",
+        "rev": "f8a9aa9ca646691f9e192a62624b1548367b5dd9",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-23.05-small",
+        "ref": "nixos-23.11-small",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -99,6 +99,22 @@
         "type": "indirect"
       }
     },
+    "nixpkgs-23-05": {
+      "locked": {
+        "lastModified": 1701699333,
+        "narHash": "sha256-ePa4oynwTNXuc4bqbi5ZMrO72yGuTPukptuMmgXPM5k=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "42499b9f6515dbca54cec1cae78165fd4e5eccfe",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-23.05-small",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixpkgs-23_05": {
       "locked": {
         "lastModified": 1684782344,
@@ -149,6 +165,7 @@
       "inputs": {
         "nixos-generators": "nixos-generators",
         "nixpkgs": "nixpkgs",
+        "nixpkgs-23-05": "nixpkgs-23-05",
         "nixpkgs-unstable": "nixpkgs-unstable",
         "simple-nixos-mailserver": "simple-nixos-mailserver"
       }

flake.nix

@@ -1,7 +1,8 @@
 {
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05-small";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11-small";
     nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable-small";
+    nixpkgs-23-05.url = "github:NixOS/nixpkgs/nixos-23.05-small";
     nixos-generators = {
       url = "github:nix-community/nixos-generators";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -9,7 +10,7 @@
     simple-nixos-mailserver.url = "gitlab:simple-nixos-mailserver/nixos-mailserver/nixos-23.05";
   };
 
-  outputs = { self, nixpkgs, nixpkgs-unstable, nixos-generators, simple-nixos-mailserver, ... }@inputs:
+  outputs = { self, nixpkgs, nixpkgs-unstable, nixpkgs-23-05, nixos-generators, simple-nixos-mailserver, ... }@inputs:
   let
     hosts = import ./hosts.nix inputs;
     helper = import ./helper.nix inputs;

hosts.nix

@@ -1,4 +1,4 @@
-{ nixpkgs, nixpkgs-unstable, ... }:
+{ nixpkgs, nixpkgs-unstable, nixpkgs-23-05, ... }:
 let
   # Set of environment specific modules
   environments = {
@@ -50,10 +50,12 @@ in
       site = "io";
     };
     mail-1 = {
+      hostNixpkgs = nixpkgs-23-05;
       site = "vs";
       environment = "proxmox";
     };
     mail-2 = {
+      hostNixpkgs = nixpkgs-23-05;
       site = "wg";
       environment = "proxmox";
     };