anchor.diff:  
         script =
           ''
  -          export PATH=${if config.nix.distributedBuilds then "${pkgs.openssh}/bin:" else ""}${pkgs.openssl}/bin:${nix}/bin:$PATH
  +          export PATH=${if config.nix.distributedBuilds then "${pkgs.openssh}/bin:${pkgs.gzip}/bin:" else ""}${pkgs.openssl}/bin:${nix}/bin:$PATH
             ${config.nix.envVars}
             exec nice -n ${builtins.toString config.nix.daemonNiceLevel} ${nix}/bin/nix-worker --daemon > /dev/null 2>&1
           '';
  
positive.code:           ''
          else "")
          + conf;
        };
  
  
        services = {
          pulseaudio = {
            enable = mkOption {
              default = false;
              description = ''
                Whether to enable the PulseAudio system-wide audio server.
                Note that the documentation recommends running PulseAudio
                daemons per-user rather than system-wide on desktop machines.
              '';
            };
  
            logLevel = mkOption {
              default = "notice";
              example = "debug";
              description = ''
                A string denoting the log level: one of
                <literal>error</literal>, <literal>warn</literal>,
                <literal>notice</literal>, <literal>info</literal>,
                or <literal>debug</literal>.
              '';
            };
          };
        };
      };
    };
  
negative.code:         ";
        };
  
        daemonNiceLevel = mkOption {
          default = 2;
          description = "
            Nix daemon process priority. This priority propagates to build processes.
            0 is the default Unix process priority, 20 is the lowest.
          ";
        };
  
  