these 2 derivations will be built:
  /nix/store/0xfmi0wm6c0dzdyxkb3191ap6dgpamk3-nixos-test-driver-postgis.drv
  /nix/store/0hpc7xpyali7rbhi7nk83ghqhl6ha9qj-vm-test-run-postgis.drv