G4PATH Improvement, master branch (2021.02.03.)
Made it possible to change the default path that G4 data files would be picked up from. This is necessary for non-standard nightlies that don't use RPMs for installing themselves on CVMFS, as discussed in ATLINFR-3946.
Once this is in, the "LCG nightlies" will need to set the following environment variable during their build:
export G4PATH=/cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/Geant4