> I really, really want the "newruntime". This kind of mistake is way too easy.
This mistake is easy, but you really should reconsider mixing such low-level code with your high-level scripts. Any use of addr, ptr, cast should be very deliberate, the analogy to Rust's unsafe is very apt here. I'm sure that even the "newruntime" will have escape hatches which will allow you to ignore the compiler, this is what you're effectively doing here. A good solution here would be to write a Nim native sscanf or just use the stdlib's parseutils or strscans.
