convention?

system-config/users/default.nix

@@ -3,10 +3,11 @@
     options.sysconfig = with lib; {
         users = let 
 
-            userType = types.submodule ({ username, ... }: {
+            userType = types.submodule ({ name, ... }: {
                 options = with lib; {
                     username = mkOption {
                         type = with types; passwdEntry str;
+                        default = name;
                     };
 
                     home-manager = {
@@ -54,7 +55,7 @@
                 };
 
                 config = {
-                    username = lib.mkDefault username;
+                    username = lib.mkDefault name;
                 };
             });