Optical photons' trajectories are not stored in the simulation when using DefaultTrackingAction, to avoid creating huge output files. If one wants to save them, OpticalTrackingAction should be used instead, only for small productions and debugging.
On the other hand, DefaultEventAction tries to access the trajectory container, to look for the hits associated with every particle and make a cut on the total deposited energy.
As a consequence, the combination of DefaultTrackingAction and DefaultEventAction produces a segmentation fault in simulations of optical photons as primary particles, since no other particles are present in the simulation.
For the same reason, using DefaultEventAction but not DefaultTrackingAction in standard simulations also causes a segmentation fault.
This PR tries to improve the error message to cover these two cases, which are the most common causes of that particular segmentation fault.
Optical photons' trajectories are not stored in the simulation when using
DefaultTrackingAction, to avoid creating huge output files. If one wants to save them,OpticalTrackingActionshould be used instead, only for small productions and debugging. On the other hand,DefaultEventActiontries to access the trajectory container, to look for the hits associated with every particle and make a cut on the total deposited energy. As a consequence, the combination ofDefaultTrackingActionandDefaultEventActionproduces a segmentation fault in simulations of optical photons as primary particles, since no other particles are present in the simulation. For the same reason, usingDefaultEventActionbut notDefaultTrackingActionin standard simulations also causes a segmentation fault. This PR tries to improve the error message to cover these two cases, which are the most common causes of that particular segmentation fault.