It doesn't make a huge difference, if you use your compiler interactively, albeit it requires some discipline to not ignore them. Absolutely do use -Werror on

It doesn't make a huge difference, if you use your compiler interactively, albeit it requires some discipline to not ignore them. Absolutely do use -Werror on CI, where nobody even looks at logs of a passing pipeline. Without -Werror you can see all your warnings at once, for better or worse.