these 2 derivations will be built:
  /nix/store/i149q8s1kp8l4hz4byk1lgavmsz6lczz-nixos-test-driver-pg_repack.drv
  /nix/store/685m0742ivbbn9spj0fc0dlpl74xyl8q-vm-test-run-pg_repack.drv