these 2 derivations will be built:
  /nix/store/z4rz96kxgxp4lxjhz32yr7wzjiphxcc9-nixos-test-driver-postgis.drv
  /nix/store/v6872xnw6sv9b9pqsb51pwd2hxp37xqq-vm-test-run-postgis.drv