anchor.diff: -import ./make-test-python.nix ({ pkgs, ... }:
  +import ./make-test-python.nix ({ pkgs, lib, ... }:
   
     {
       machine = { pkgs, ... }:
  
positive.code:       machine.succeed(
            "journalctl -eu zigbee2mqtt | grep \"Error: Error while opening serialport 'Error: Error: No such file or directory, cannot open /dev/ttyACM0'\""
        )
      '';
    }
  )
  
negative.code:         services.zigbee2mqtt = {
            enable = true;
          };
  
          systemd.services.zigbee2mqtt.serviceConfig.DevicePolicy = lib.mkForce "auto";
        };
  
      testScript = ''
  