anchor.diff:          comm <(sort -n baseFiles|uniq) \
                <(sort -n layerFiles|uniq|grep -v ${layer}) -1 -3 > newFiles
           # Append the new files to the layer.
  -        tar -rpf temp/layer.tar --mtime="@$SOURCE_DATE_EPOCH" \
  +        tar -rpf temp/layer.tar --hard-dereference --mtime="@$SOURCE_DATE_EPOCH" \
             --owner=0 --group=0 --no-recursion --files-from newFiles
   
           echo "Adding meta..."
  
positive.code: 
          echo "Packing layer..."
          mkdir $out
          tar -C layer --mtime="@$SOURCE_DATE_EPOCH" -cf $out/layer.tar .
  
          # Compute the tar checksum and add it to the output json.
          echo "Computing checksum..."
  
negative.code: 
        postMount = ''
          echo "Packing raw image..."
          tar -C mnt --hard-dereference --mtime="@$SOURCE_DATE_EPOCH" -cf $out .
        '';
      };
  
  