UPDATE:
@ax3l The `examples/KelvinHelmholtz/cmakeFlags`do contain a test **with radiation**. Therefore, **we need the old version.**

see test number 2 [here](https://github.com/ComputationalRadiationPhysics/picongpu/blob/33b1e4b55b8774f503d94462ab98b6fb3a602ba1/examples/KelvinHelmholtz/cmakeFlags#L34)