We have a lot of different execution environments (compiled to JS with debug compiler, compiled to JS with optimizing compiler, JIT VM, AoT VM, bytecode interpreter, Android, iOS, etc.) so that makes it a little more complex.

We do have allocation tracking in some of those, but that doesn't always get you as much as you'd expect. Discovering that, say, "oh, this list was deserialized by the JSON API" still means it could have come from dozens of different regions of the program.

I would expect the debug allocator would need to be a full stack trace, file and line on their own would probably not be helpful. This is probably doable if they cache the allocation paths. But it would be interesting to hear about what tooling they've added to track these issues.