anchor.diff:            gc-keep-outputs = true
             gc-keep-derivations = true
           ";
  -        description = "
  -          This option allows to append lines to nix.conf.
  -        ";
  +        description = "Additional text appended to <filename>nix.conf<filename>.";
         };
   
         distributedBuilds = mkOption {
  
positive.code:               + " ${machine.sshKey} ${toString machine.maxJobs} "
                + (if machine ? speedFactor then toString machine.speedFactor else "1" )
                + "\n"
              ) config.nix.buildMachines));
            target = "nix.machines";
          };
  
      jobs.nixDaemon =
        { name = "nix-daemon";
  
          startOn = "startup";
  
          path = [ nix pkgs.openssl pkgs.utillinux ]
            ++ optionals config.nix.distributedBuilds [ pkgs.openssh pkgs.gzip ];
  
          script =
            ''
              ${config.nix.envVars}
              exec \
                nice -n ${builtins.toString config.nix.daemonNiceLevel} \
                ionice -n ${builtins.toString config.nix.daemonIONiceLevel} \
                nix-worker --daemon > /dev/null 2>&1
            '';
  
          extraConfig =
            ''
              limit nofile 4096 4096
            '';
        };
  
      environment.shellInit =
        ''
          # Set up the environment variables for running Nix.
          ${config.nix.envVars}
  
          # Set up secure multi-user builds: non-root users build through the
          # Nix daemon.
  
negative.code: with pkgs.lib;
  
  let
  
    cfg = config.nix;
  
    inherit (config.environment) nix;
  
  