these 4 derivations will be built:
  /nix/store/nl5jlq9l8zqa5pcvi185qr2n5zs7jjg8-docker-image-sources.drv
  /nix/store/fnfpsy2d8l0k7d6n4jrdsdd75zmw40fn-docker-image-packages-manifest.drv
  /nix/store/zh142qq7lh9b24li3xj0n4yjg24kd15n-docker-image-inputs.drv
  /nix/store/5x5hc5ag4w5b305x3acxpv8j0a0d273j-docker-image-inputs-hash.drv