anchor.diff:        ${preBootCommands}
         $machine->waitForUnit("multi-user.target");
         $machine->copyFileFromHost(
  -          "${ makeConfig { inherit grubVersion grubDevice grubIdentifier extraConfig; readOnly = false; forceGrubReinstallCount = 2; } }",
  +          "${ makeConfig { inherit grubVersion grubDevice grubIdentifier extraConfig; forceGrubReinstallCount = 2; } }",
             "/etc/nixos/configuration.nix");
         $machine->succeed("nixos-rebuild boot >&2");
         $machine->shutdown;
  
positive.code: 
    # The configuration to install.
    makeConfig = { grubVersion, grubDevice, grubIdentifier
                 , extraConfig, readOnly ? true, forceGrubReinstallCount ? 0
                 }:
      pkgs.writeText "configuration.nix" ''
        { config, lib, pkgs, modulesPath, ... }:
  
negative.code:         boot.loader.grub.fsIdentifier = "${grubIdentifier}";
  
          boot.loader.grub.configurationLimit = 100 + ${toString forceGrubReinstallCount};
  
          hardware.enableAllFirmware = lib.mkForce false;
  
  