This is astonishing. Is anyone else surprised at this dead code figure? Is it a feature of large projects I've just never noticed?
The 1.8% feels high if it's trivially dead. When I've run simple static analysis on decent codebases before, it's been much lower. For non-trivial dead code, it might be low. E.g. a lot of projects have piles of "dead" code behind ancient feature flags that would never be switched.
A small amount of dead code is fine. E.g. it might not be worth deleting utility methods that you happen to remove the last use of if they are simple and you might re-add a use later. Generated code is often dead since it's not worth specifying to the generator exactly what will be used. Other times, deleting dead code can lead to a valuable cascade of other deletions and simplifications.
That hasn't been a unique experience either -- quite the opposite. Codebases bloat over time. The only thing astonishing to me is that in something as large as Bun they only found 11k lines.
In practice, it's annoying to track if those small util functions become dead code.
in practice the exponential explosion of options may become intractable. lets say you have 10 compilation flags with 10 options each. not syre you want the compiler scanning through all that on each pass
It's bog standard, very mild technical debt.