these 3 derivations will be built:
  /nix/store/x7k16spdsblnqw6n55s7hr52vad5kmqq-docker-image-sources.drv
  /nix/store/0dd2xylnkr0r1gbd7y1k1pmmy9z8f8vd-docker-image-inputs.drv
  /nix/store/aapjldibdr6y3n0z7qfaa40mc7wgqgsg-docker-image-inputs-hash.drv