these 3 derivations will be built:
  /nix/store/4fck7cbnq8nxdkr0b31ywqkci66r9g1w-v3.15.1.tar.gz.drv
  /nix/store/yzj7y85idk04s00rahgz4ayj9psca4dw-python-vendor.drv
  /nix/store/njvh78hjlmcfj2kz9vbmvwma5fss3hc5-bernstein-3.15.1.drv