Missing ancestor information

[francois-drielsma]

I'm submitting a ...

• bug report
• feature request

Expected Behavior

All larcv::Particle should be assigned an ancestor particle.

Current Behavior

Certain particles are not assigned an ancestor particle. See below:

Possible Solution (optional)

Anecdotally, it seems the issue appears with showers only. This could be related to the ancestor (primary) particle being dropped before the Supera process is run, in which case Supera simply cannot find the ancestor.

How to reproduce

Appears occasionally in producing all larcv.root MC files.

Checklist

• I've added at least 1 label
• Assigned a reviewer

[bear-is-asleep]

I think this is solved by #56 @francois-drielsma . But we should leave this open until we confirm.

[aliciavr]

From the SBND Fall Analysis workshop we have seen this example regarding the bug, in the file larcv_mc_20250729_220114_139358-e726b149-4070-45ff-9490-bda42039ffe2_spine.h5
Run 3487, Subrun 2, Event 38, Entry 3