these 2 derivations will be built:
  /nix/store/piyc3fdr057ldcqpbibivydp5kbxrybf-nixos-test-driver-pgtap.drv
  /nix/store/ch8zslvjrlbfy5lkn0wksi7yqmqngli0-vm-test-run-pgtap.drv