Erg, yeah good catch, thank you. I like to think that constants are truly untyped, but that's wrong. :)
Luckily, it looks like we didn't hit this case much in practice or not any case that was important enough for someone to report a bug about it. This makes sense since the scavenger isn't quite as useful in the context of, say, a CLI tool, where it's more likely this case could happen (e.g. laptop lid closes during the section where we're measuring time). I'll send a fix, but it's probably not worth backporting.