(Note: I am a long time systems software developer but I don't use Rust, so while this made perfect sense to me maybe it shouldn't have due to some Rust thing I

(Note: I am a long time systems software developer but I don't use Rust, so while this made perfect sense to me maybe it shouldn't have due to some Rust thing I don't know about.) I'm guessing the issue is how there is really a stage between "debug" and "release" where you need the code to run fast enough to be worth testing and using but you don't need to eek out then final 0.5% of performance by cranking all the settings. When working on such projects you only drop down to a "debug build" if you end up entirely screwed trying to figure out why something is broken because the optimizer has messed up the debugger, and you care OK with the lower performance as you've already isolated the issue.