these 2 derivations will be built:
  /nix/store/4gb88n8kgh6vik0xvd8ywg47qli3w9gl-nixos-test-driver-pg_tle.drv
  /nix/store/v9ijq3ihkvygmbh494f7q1zgid022phk-vm-test-run-pg_tle.drv