structuredAttrs is enabled

trying https://chromium.googlesource.com/external/khronosgroup/webgl.git/+archive/714857a28445e8f5d8d6ae1c78498578009534d8.tar.gz
  % Total    % Received % Xferd  Average Speed  Time    Time    Time   Current
                                 Dload  Upload  Total   Spent   Left   Speed
100 19.86M   0 19.86M   0      0  3.61M      0           00:05          3.65M
unpacking source archive /build/714857a28445e8f5d8d6ae1c78498578009534d8.tar.gz