Answering my own question, apparently `brk #1` is insufficient on Apple silicon. That results in just a trap and will prevent the debugger from continuing past the debug statement. From a bit of searching and my experiments `brk #0xF000` was the way to go instead which had the consequence of not always landing on the debug statement, the addition of a nop with `brk #0xF000 \n nop` resulted in the debugger landing on the correct statement.
I didn't come across any good ones when creating this library, but if you're using VSCode, I tried my best to make the README as beginner friendly as possible. I'm open to issues and PRs if anything is unclear. I think part of the issue is that debugging is not yet very common in the Rust ecosystem, partially due to the excellent borrow checker and error messages, but partially due to immature tooling, hence I made this to promote the practice of debugging.
I can understand where you're coming from, but when programming games you generally don't want a breakpoint to be hit more than once since you are running a loop over multiple frames. So in this case the concept of ensure_once is more common, so the shorter inverse is more convenient. Asserts should be enough to get your attention and not to annoy, so orienting it this way is a deliberate choice.
Interesting. Unfortunately, I'm not well versed in assembly, is there a similar trick or requirement in arm and would that include Apple silicon, or is this something specific to `int3` on x86? That may explain why it was inconsistent during my development process, I didn't think to check if the inconsistency was platform dependent.