these 2 derivations will be built:
  /nix/store/lkdv5d8yc8cqlkc9y2l9wksl5lvzya1n-nixos-test-driver-pg_repack.drv
  /nix/store/z6q81bxxycccby7y1w2090y9i8n06xcb-vm-test-run-pg_repack.drv