make home manager optional

helpers/default.nix

@@ -1,7 +1,7 @@
 {lib, ...}: {
   mkIfElse = p: yes: no:
     lib.mkMerge [
-      (mkIf p yes)
-      (mkIf (!p) no)
+      (lib.mkIf p yes)
+      (lib.mkIf (!p) no)
     ];
 }

modules/default.nix

@@ -23,7 +23,7 @@ in {
     services.openssh = {
       enable = true;
       settings = {
-        PermitRootLogin = helpers.mkIfElse config.my.server.enable "yes" "no";
+        # PermitRootLogin = "no"; # this is managed through authorized keys
         PasswordAuthentication = false;
         KbdInteractiveAuthentication = false;
       };

modules/home/default.nix

@@ -6,12 +6,13 @@
 }: let
   cfg = config.my.home;
 in {
-  imports = [
-    ./vinzenz.nix
-    ./ronja.nix
-    # enable home manager
-    <home-manager/nixos>
-  ];
+  imports =
+    [
+      ./vinzenz.nix
+      ./ronja.nix
+      # enable home manager
+    ]
+    ++ lib.optional (builtins.pathExists <home-manager/nixos>) <home-manager/nixos>;
 
   options.my.home = {
     enable = lib.mkEnableOption "my home management";