structuredAttrs is enabled

trying https://github.com/quietpublish/mardi-gras/archive/refs/tags/v0.30.1.tar.gz
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed

  0      0   0      0   0      0      0      0                              0
  0      0   0      0   0      0      0      0                              0
  0      0   0      0   0      0      0      0                              0

  0      0   0      0   0      0      0      0                              0
100  8.14M   0  8.14M   0      0  8.69M      0                              0
100  8.14M   0  8.14M   0      0  8.69M      0                              0
100  8.14M   0  8.14M   0      0  8.69M      0                              0
unpacking source archive /nix/var/nix/builds/nix-894267-3751996404/download.tar.gz