these 2 derivations will be built:
  /nix/store/bqp3fi88j7xfb7s4fz3wpz0639ik261i-nixos-test-driver-pgtap.drv
  /nix/store/gp0vnr8bmabjfp0ssq4hd0d1cg373vba-vm-test-run-pgtap.drv