these 3 derivations will be built:
  /nix/store/kjxbaxvi39ksxv1wv4mlpjyavcx7bd1w-freebuff-linux-x64.tar.gz.drv
  /nix/store/1iv3l6k85z2z8bvkyimdlsnwv7wwl6nh-freebuff-0.2.13.drv
  /nix/store/4hr3dllazbayrbv8hjggvmm1y11w2bwx-check-freebuff.drv