structuredAttrs is enabled

trying https://github.com/mayth/go-simple-upload-server/archive/v2.2.0.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  19461   0  19461   0      0  26279      0                              0
100  19461   0  19461   0      0  26278      0                              0
100  19461   0  19461   0      0  26276      0                              0
unpacking source archive /nix/var/nix/builds/nix-15694-1172949709/download.tar.gz