The bug could totally happen in Julia. The point was your question: "What happens for that scientist when they have to dive into Julia’a stack to debug something weird?"

And then claimed that this was somehow better in Python + C, which is not my experience. I expect this to be easier in Julia than in Python and C.

I totally agree that the tooling is not where it needs to be, btw, but now that the target has stopped moving I expect it to get there soon.