these 2 derivations will be built:
  /nix/store/xrcc61hwgpz1jj6bd6c94vznf34aiz79-nixos-test-driver-pg_repack.drv
  /nix/store/7qngmhblp2b49ra16nmd38mhpxxaix61-vm-test-run-pg_repack.drv