anchor.diff:        }
   
         {
  -        assertion = !optimusCfg.enable ||
  -          (optimusCfg.nvidiaBusId != "" && optimusCfg.intelBusId != "");
  +        assertion = !syncCfg.enable ||
  +          (syncCfg.nvidiaBusId != "" && syncCfg.intelBusId != "");
           message = ''
             When NVIDIA Optimus via PRIME is enabled, the GPU bus IDs must configured.
           '';
  
positive.code:   enabled = nvidia_x11 != null;
  
    cfg = config.hardware.nvidia;
    optimusCfg = cfg.optimus_prime;
  in
  
  {
    options = {
      hardware.nvidia.modesetting.enable = mkOption {
        type = types.bool;
  
negative.code:         Enable kernel modesetting when using the NVIDIA proprietary driver.
  
          Enabling this fixes screen tearing when using Optimus via PRIME (see
          <option>hardware.nvidia.prime.sync.enable</option>. This is not enabled
          by default because it is not officially supported by NVIDIA and would not
          work with SLI.
        '';
      };
  
      hardware.nvidia.prime.sync.enable = mkOption {
        type = types.bool;
        default = false;
        description = ''
  