structuredAttrs is enabled

trying https://hackage.haskell.org/package/nix-diff-1.0.21/revision/1.cabal
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed
100   3693   0   3693   0      0   5359      0                              0