these 2 derivations will be built:
  /nix/store/vckx4sndhcjiy7p4xvmgh7dxmha2xr6v-nixos-test-driver-pgtap.drv
  /nix/store/5w5n2dkivn71a4hv66wxfbrbc2v801sc-vm-test-run-pgtap.drv