see https://github.com/derofim/cling-cmake
HOT code reload
possible approaches:
store app state
fix cling undo for files
https://root-forum.cern.ch/t/loading-unloading-class-as-interpreted-macro-in-cling-multiple-times/32976/2
execute cling code to change callbacks & variables
nested cling::Interpreter with multiple cling::MetaProcessor
IDK how to do it, but you can create child cling::Interpreter
see https://github.com/derofim/cling-cmake