MCEventHeader misses directory?

O²
1

Dear Experts,

I have a code that used to work. Now I got the following error message:

Error in TTree::SetBranchAddress: Unable to determine the type given for the address for “MCEventHeader.”. This is probably due to a missing dictionary, the original data class for this branch is o2::dataformats::MCEventHeader.

I checked the simulation output Kine file and it does contain MCEventHeader. branch. I alos checked O2 codes and I think the dataformat I try to use is correct. I try to access in the following way:

  TTree *kineTree = (TTree *)fKine->Get("o2sim");
  o2::dataformats::MCEventHeader *mcHeader = nullptr;
  kineTree->SetBranchAddress("MCEventHeader.", &mcHeader);

Other branches like the MCTracks have no such problem.
I use an up-to-date O2.

Thank you in advance

2

Quickly checked this on my Mac (in a ROOT prompt). I don’t see any problems in my case. Can you share platform, O2 commit, etc?

3

Thanks for the answer. I’m still testing, may be some header is out dated. I’m working on WSL2 and my O2 is from 6th of September (commit e10235b536862f2fe690a9cbf5f3efd5abfd817d).
The macro I try to run worked in the beginning of the year, if I recall correctly.

4

Okay, got it. Interesting problem, though. My headers weren’t in the correct order.
Wrong:

#include "SimulationDataFormat/MCEventHeader.h"
#include "SimulationDataFormat/MCTruthContainer.h"

Correct:

#include "SimulationDataFormat/MCTruthContainer.h"
#include "SimulationDataFormat/MCEventHeader.h"

Thanks!

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