[a_t48]

In my experience the warnings tend to pile up. Once you have a few warnings in the codebase, what's a few more?

[throwaway43234]

I think a good compromise is warnings aren't allowed in the final committed code (this can be enforced either by convention or with git hooks), but whatever you do locally is between you and your compiler. "What happens in the devbox stays in the devbox"

[a_t48]

I'd tend to agree, though this can be harder to set up than just having a consistent build config for all platforms.

[saagarjha]

Generally I would hope that your CI build allows you to set this kind of configuration. (At the very least, you must have this as an option, because someone will run into it at some point and will have to turn your -Werror off.)