these 3 derivations will be built:
  /nix/store/jrvqp391vpgxzf8md26xafz816nd8gy7-serde_json-1.0.152.drv
  /nix/store/dnkz3kcafcq4ph6fsbb7yaxsi35r3nyq-cargo-vendor-dir.drv
  /nix/store/bln27vkmrkkjl0h5rdfy2x1vqk5rss1s-bob-0.1.0.drv