structuredAttrs is enabled

trying https://github.com/FalcoSuessgott/vkv/archive/v1.0.0.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
100 879.1k   0 879.1k   0      0  1.00M      0                              0
100 879.1k   0 879.1k   0      0  1.00M      0                              0
100 879.1k   0 879.1k   0      0  1.00M      0                              0
unpacking source archive /nix/var/nix/builds/nix-29372-4245051612/download.tar.gz