Which is a good example on how managed runtimes are already not deterministic and how hard it is to reproduce scenarios.

I agree, in my original comment, I went out of the way to say “C” in my hypothetical argument.

But even with C, it’s still not completely deterministic with out of order and predictive branching, cache hits vs misses etc. Didn’t exactly this cause some of the worse processor level security issues we had seen in years?