How can datasets be really optional?

Applications
1

When I try to run a simple Geant4 application https://github.com/jintonic/mingle/blob/main/mingle.cc in an interactive mode with GEANT4_DATA_DIR set to a wrong place, I’ll get the following error message:

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : PART70000
      issued by : G4NuclideTable
G4ENSDFSTATEDATA environment variable must be set
*** Fatal Exception *** core dump ***
 **** Track information is not available at this moment
 **** Step information is not available at this moment

-------- EEEE -------- G4Exception-END --------- EEEE -------

Does Geant4 try to load datasets even at the Idle state? If datasets are truly optional, Can I get to the idle state without datasets?

Thanks,

Jing

2

Closing as a duplicate of Is there a reference physics list that does not use any optional dataset? (which is a better location for the question anyway).