Hi, I'd like to suggest turning on -Werror on at least the GTK and WPE EWS, to reduce the amount of time I spend cleaning up newly-introduced build warnings. ;) If we're worried about too many spurious build failures, let's at least build with a few flags to prevent the most common GCC warnings that developers using Clang will never notice: -Werror=return-type, -Werror=class-memaccess, and -Werror=pessimizing-move. These are simple to avoid if you see the warning from GCC, but very easy to miss if you develop with Clang. I guess these account for more than half of new GCC warnings introduced into WebKit. I'd also like to see -Werror=unused, since it's easy to introduce these warnings for other ports when doing anything involving conditional compilation. That might require some CMake changes, though (as we don't want to break -Wno-unused-parameter, which we use when building Source/WebKit and several directories under Tools). But really, rather than cherry-picking particular warning flags, using -Werror seems simplest to me. Problematic warnings should be disabled or suppressed. I do *not* suggest using -Werror on any non-EWS bots, since that will make gardening harder for almost no benefit. We do not want to lose test results due to a missing UNUSED_PARAM() or RELEASE_ASSERT_NOT_REACHED() somewhere. I also certainly do not suggest using it by default in CMake, which would really annoy our distributors. I would only use it in the EWS bot config. Michael