anchor.diff:              read password
   
               if ! curEnt=$(getent passwd "$name"); then
  -                echo "creating user $name..."
                   useradd --system \
                       "$name" \
                       --comment "$description" \
  
positive.code:              calls in `libstore/build.cc', don't add any supplementary group
               here.  */
            uid = builtins.add ids.uids.nixbld nr;
            group = "nogroup";
            extraGroups = ["nixbld"];
          };
  
        nixBuildUsers = map makeNixBuildUser (pkgs.lib.range 1 10);
  
negative.code: 
      system.activationScripts.users = fullDepEntry
        ''
          echo "updating users..."
  
          cat ${usersFile} | while true; do
              read name || break
              read description
  