these 2 derivations will be built:
  /nix/store/sr0yjqysix7gghn9v7lqadiwi7pl10w2-nixos-test-driver-pgroonga.drv
  /nix/store/xkq0bgga266am99qycm0vybq0fmkdy5f-vm-test-run-pgroonga.drv