Hello all ! I've been recently testing the functionality of writing Snapshot with Vary'ed quantities discussed in #11218 and related to the PR in #19725.

When I try to apply a Filter on a quantity that's Vary'ed and save that quantity to a Snapshot including its variations the code crashes with a segmentation fault. I'm attaching the stack trace for the segmentation fault. I am running this in a EL9 container, with the dev3 LCG build of today (/lcg/views/dev3/latest/x86_64-el9-gcc15-opt/).

stack_trace.txt

The crash doesn't happen if I:

• store the quantity and variations before applying the Filter
• store the quantity without variations after applying the Filter

I attach a MWE with the three scenarios, including three ways to apply Vary() so you can test it yourselves.

mwe_snapshot_vary_filter_crash.py

Tagging @hageboeck, @vepadulano and @martamaja10 as they were the ones tagged in the original issue.