The function triggering the error is the ->paster() bit. .... Could be XML::Twig::Elt has problems handling large structures. I would refactor my module then to write to file in smaller chunks. But before I do that I'd like to ask if someone sees what I am doing wrong here.

How did you determine it is the paste bit that triggers the segfault?

What happened when you upgraded all dependencies?

You should write a program with the express purpose of trying to replicate this crash, say, ~50000 pastes of a similar sort