these 2 derivations will be built:
  /nix/store/k6a0npwxkjpvwn9il0kqkm2vzfq49d54-cargo-vendor-dir.drv
  /nix/store/hbcjn3p0za1nrgccaxl0l28ir3w0f1b0-horae-0.1.0.drv