these 2 derivations will be built:
  /nix/store/nkldyr12r37l5346xdgagha0lqfjwi0p-nixos-test-driver-pg_repack.drv
  /nix/store/1w55kjh17rjzjnmsf2yji5x7arzwi9lw-vm-test-run-pg_repack.drv