these 2 derivations will be built:
  /nix/store/8nslc9hnnxan1mfpnf62srrhwdlqcgxp-nixos-test-driver-site.drv
  /nix/store/rpmdnz8b2wav5q8hdwk9yas5m1k5w9zp-vm-test-run-site.drv