these 2 derivations will be built:
  /nix/store/bz46s2mw9gpa6y3bvkd0zbikxavqwvhg-nixos-test-driver-postgis.drv
  /nix/store/wz2hiw1mlb61yyhlc5sj5wbgny3hg40n-vm-test-run-postgis.drv