these 3 derivations will be built:
  /nix/store/xl45cvwrvz2wgyj53cm0ix2bc1mdkkvz-libc-0.2.189.drv
  /nix/store/i8p2id843zx6k0cz5rly44a4pn292m77-cargo-vendor-dir.drv
  /nix/store/9ysnfsd6h2943djcsjydkfnph2i5sgwi-bob-0.1.0.drv