This is something I was thinking about based on this comment, but would apply to iOS as well (and macOS): the way the native code for plugins on some platforms is built, the build environment may change in ways that create warnings (e.g., the way the Flutter tool updates the min deployment version on iOS to match the app's min deployment version frequently creates deprecation warnings that don't exist in our builds), so we generally don't want to make warnings errors to avoid breaking plugin clients. However, that means warnings aren't surfaced in our CI, which in practice means we don't notice when new ones are added by PRs, which makes warnings kind of useless.

I think we should consider either:

1. modifying the build on disk before building in CI to add -Werror, or
2. add build output parsing to notice errors, and fail the CI step.

Both have some maintenance complexity, but continuing to ignore warnings on the native side doesn't seem like a good option.

/cc @blasten @jmagman