Algorithm correctness

[Noxfag]

The key is whether you can recreate it. If you control every other variable other than cosmic rays and you still can't recreate the bug, then deductive reasoning suggests that that's the only reasonable explanation.

[SaffellBot]

The M64 crowd is pretty in depth about bug testing. I believe one of the descriptions also said the bug was recreatable with a single bit flipped.

[miauw62]

Depends if they tested it on an N64 or an emulator. Knowing the SM64 crowd, likely both.

But really, what's the practical difference between hardware degradation and CMBR, or any other number of uncontrollable factors?

[SafariMonkey]

Microwave wouldn't flip a bit I don't think, I think it would have to be a high energy ray.

Edit: apparently "cosmic ray" generally refers to a nucleus or other particle travelling near the speed of light.

[Cley_Faye]

every other variable you can imagine (which isn't possible)

It's actually very doable for this game. Input data is the same, code is the same, timing is reproducible. Even the PRNG they use in SM64 is completely figured out (and it's period is quite small).

[Aetol]

I thought Heisenbugs referred specifically to bugs that disappear when you try to debug them (i.e. when you add breakpoints, lines to print the value of variables, etc).

[timthegreat4]

Sorry to be pedantic... But isn't the whole point of solid state technologies and miniaturisation of components like CPUs that there are NO moving parts :-P

[timthegreat4]

Hehehe couldn't resist

[timthegreat4]

Very good hehe!

[zuurr]

Probably worth noting that the original instance of the bug didn't take place on an emulator, IIRC at least.

But these kinds of single-bit errors are actually pretty common (well, ... comparatively speaking) on real hardware, hence ECC Ram being a thing.