these 3 derivations will be built:
  /nix/store/9hdgpmiq4jriafksj5yhmxlqi2sarp1j-docker-image-sources.drv
  /nix/store/9fj0klidkz5da58a8y21hxm3dwlsggyz-docker-image-inputs.drv
  /nix/store/lzhvpi72ryr6bvpcdmyy7n1mrgprjij2-docker-image-inputs-hash.drv