container friendly passing of current system

flake.nix

@@ -33,12 +33,13 @@
             ./common/common.nix
             inputs.simple-nixos-mailserver.nixosModule
             inputs.agenix.nixosModules.age
-            {
+            ({ lib, ... }: {
               environment.systemPackages = [ inputs.agenix.defaultPackage.${system} ];
               
               # because nixos specialArgs doesn't work for containers... need to pass in inputs a different way
               options.inputs = lib.mkOption { default = inputs; };
-            }
+              options.currentSystem = lib.mkOption { default = system; };
+            })
           ];
           # specialArgs = {};
         };