these 2 derivations will be built:
  /nix/store/9p0v8h3r177x40w90qr3aa3f845lyig3-openfang-0.6.9-vendor.drv
  /nix/store/m8ss1nnx8dfnpg5azv0j9h5awvmywh8k-openfang-0.6.9.drv