these 3 derivations will be built:
  /nix/store/6710b2a6ygj8svvqq42s3c4wqis1x6ss-serde_json-1.0.152.drv
  /nix/store/f3swgf38vzqmsiqjfasvpsa6qj4xhi92-cargo-vendor-dir.drv
  /nix/store/0l0jck57ay6ncyfc8qh2cwf57n3xjvm8-bob-0.1.0.drv