these 6 derivations will be built:
  /nix/store/9pqd2jsg99hvqimrlsr2xlsbg4p0ljqm-nixos-system-server-test.drv
  /nix/store/mq3anmp35c2j2nfpllrm7ald7d7p1bzn-closure-info.drv
  /nix/store/1v2w3zhqm2973dy5qxhks1nrh8xc13zg-run-nixos-vm.drv
  /nix/store/nv1n8lzl9bwm6nqzv8ipl48m3s2jnyrw-nixos-vm.drv
  /nix/store/ih9b5c57ajb4i1rhi1463snsyihlbhnx-nixos-test-driver-postgis.drv
  /nix/store/fm8xc3j4xzzghy9w9fkhr3nzgyw8l79l-vm-test-run-postgis.drv