these 3 derivations will be built:
  /nix/store/9pf205c4ldallrkq0h05ixm4l5vqmz80-libc-0.2.189.drv
  /nix/store/di2n9grr11q4ppsl5bqvc93mlh52iihv-cargo-vendor-dir.drv
  /nix/store/7y36imf6bkkphwq0x0xlmiiyr014lfrl-bob-0.1.0.drv