anchor.diff:          list = if lib.any (n: item == n) [ "tar" "zip" ] then [ ] else [ item ];
           rest = if item == "tar" then lib.tail rest' else rest';
         in list ++ removeTarZip rest;
  +
  +  versions = {
  +    "1" = {
  +      brotli = brotli_0-4-0;
  +      tar = gnutar_1-29;
  +    };
  +    "2" = {
  +      brotli = brotli_0-5-2;
  +      tar = gnutar_1-29;
  +    };
  +  };
  +
  +  inherit (versions."${version}")
  +    brotli
  +    tar;
   
     urls' = (if url != null then [ url ] else [ ]) ++ urls;
   
  
positive.code: { lib
  , fetchurl
  , unzip
  }:
  
  { # Optionally move the contents of the unpacked tree up one level.
  
negative.code:     date -d "@$mtime" --utc >&2
    '' + ''
      echo "Building Archive ${name}" >&2
      ${tar}/bin/tar --sort=name --owner=0 --group=0 --numeric-owner \
        --no-acls --no-selinux --no-xattrs \
        --mode=go=rX,u+rw,a-s \
        --clamp-mtime --mtime=@$mtime \
        -c "${name'}" | ${brotli}/bin/brotli --quality 6 --output "$out"
      du -bhs "$out"
      cp "$out" "$TMPDIR/${name}"
    '';
  