Hi, there seem to be a inconsistency how CLHEP is treated in different versions and this causes dependent software problems. 1. In lib64/Geant4-10.2.3/Geant4Config.cmake it's defined set(CLHEP_ROOT_DIR "__path_to_CLHEP__") find_package(CLHEP 2.3.1.1 REQUIRED ) which also defines CLHEP_INCLUDE_DIRS 2. In lib64/Geant4-10.3.3/Geant4Config.cmake it's defined set(CLHEP_ROOT_DIR "__path_to_CLHEP__") find_package(CLHEP 2.3.4.3 REQUIRED ) which also defines CLHEP_INCLUDE_DIRS 3. In lib64/Geant4-10.4.0/Geant4Config.cmake CLHEP_ROOT_DIR disappears and you only have set(CLHEP_DIR "__path_to_CLHEP__/lib/CLHEP-2.4.0.0") which points to lib find_package(CLHEP 2.4.0.0 EXACT REQUIRED CONFIG) which also defines CLHEP_INCLUDE_DIRS We(DD4hep) usually used CLHEP_ROOT_DIR but this is not possible since 10.4, now we infer the location of CLHEP from the CLHEP_INCLUDE_DIRS. Was this intentional? Cheers, Marko
This is due to the change from using our own "FindCLHEP" module to the use of CLHEP's provided "CLHEPConfig.cmake" file. The later is now, and will be, the way in which CLHEP is located and configured. CLHEP_ROOT_DIR won't be supported going forward and it's not a standard variable, and may not be reliable in all cases (it's highly dependent on how the client packaged/installed CLHEP).
