Comment by dmoy
16 hours ago
> Debug compiles super fast and allows unused variables etc, but the resulting binary runs super slowly, maybe with extra safety checks too, like the race detector.
At least in the golang / unused-vars at Google case, allowing unused vars is explicitly one of the things that makes compilation slower.
In that case it's not "faster compilation as in less optimization". It's "faster compilation as in don't have to chase down and potentially compile more parts of a 5,000,000,000 line codebase because an unused var isn't bringing in a dependency that gets immediately dropped on the floor".
So it's kinda an orthogonal concern.
Accidentally pulling in a unused dependency during development is, if not a purely hypothetical scenario, at least an extreme edge case. During debug, most of the times you already built those 5000000000 lines while trying to reproduce a problem on the original version of the code. Since that didn’t help, you now want to try commenting out one function call. Beep! Unused var.
Right, I meant that the binary should run slowly on purpose, so that people don't end up defaulting to just using the debug build. A nice way of doing so without just putting `sleep()`s everywhere would be to enable extra safety checks.