Have to read through this as I wonder how that's even possible for a lib of that caliber for such a long time. Afaik ABI breaks pretty easily if one just adds more fields to a struct. So you must have planned ahead very well to keep it ABI stable and upgradable, I guess.

@pythno a combination of planning, luck and dedication I suppose. We don't change structs once introduced (with one exception that I can recall and that works since we only provide a pointer to it)