these 3 derivations will be built:
  /nix/store/5fsm0wfn8z731w1bz3jn2gmcl0n599rn-docker-image-sources.drv
  /nix/store/kyknfcpwl9npij4509bx6kzpnw3isg9h-docker-image-inputs.drv
  /nix/store/m1yvqns25aaqvx582jdfincyhinkq1nk-docker-image-inputs-hash.drv