Problem calling twice to runmanger

[makotoasai]

We have no plan to make Geant4 kernel re-instantiatable.
Maybe this post is helpful.

Reset run manager/kernel in single process

Digging through the Geant4 source code led me to the conclusion that G4RunManager and G4RunManagerKernel are fundamentally hostile to this idea. I’m using Catch2 which integrates with cmake's ctest. This gives me two, far from ideal but tolerable options: ctest runs different Catch2 TEST_CASEs in separate processes. So two different test cases can set up their own run manager, and not interfere with each other at all. Therefore simply typing ctest works—it runs all the tests without any dang…