New comment by paper42 on void-packages repository

https://github.com/void-linux/void-packages/pull/40423#issuecomment-1318563511

Comment:
> The `-DVTK_MODULE_USE_EXTERNAL_vtknlohmannjson=OFF` configure arg did not help to avoid `CMake Warning at CMake/vtkModule.cmake:4572 (find_package): By not providing "Findnlohmann_json.cmake" in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by "nlohmann_json", but CMake did not find one.`. Used `DVTK_USE_EXTERNAL=OFF` instead. I'm not sure if this is problematic.

We definitely want to use system dependencies, can we fix it by adding json-c++ to makedepends?