anchor.diff:      '';
     };
   
  +  check = mkAssert (!(config.services.rpcbind.enable && config.services.portmap.enable))
  +    "Portmap and rpcbind cannot both be enabled.";
   
   in
   
  
positive.code: 
    ###### implementation
  
    config = mkIf config.services.rpcbind.enable {
  
      environment.systemPackages = [ pkgs.rpcbind ];
  
  
negative.code:         serviceConfig.ExecStart = "@${pkgs.rpcbind}/bin/rpcbind rpcbind";
        };
  
    });
  
  }
  