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:         ";
        };
  
  
        daemonNiceLevel = mkOption {
          default = 2;
          description = "
            nix dameon process priority. This priority propagates to build processes.
            0 is default unix process priority. 20 is lowest.
          ";
        };
  
  
negative.code:           ''
          else "")
          + conf;
        };
      };
    };
  