I recently got build failures after upgrading to XCode 11. I'm opening this meta bug to track them.
Maybe we need to make it official that Xcode 10 is needed to build WebKit on Mojave. I don't think that it's practical for us to maintain compatibility with multiple Xcode versions on each OS.
Not sure that will work well with bug 199852 and that seems inconsistent with the current Mojave bot setup (which uses Xcode 11.1). I guess the remaining issue (bug 199705) will resolve once Xcode 11.1 is released.
(In reply to Frédéric Wang (:fredw) from comment #2) > Not sure that will work well with bug 199852 and that seems inconsistent > with the current Mojave bot setup (which uses Xcode 11.1). I guess the > remaining issue (bug 199705) will resolve once Xcode 11.1 is released. I think part of the confusion is that there are two separate issues: 1) Building WebKit for iOS using Xcode 11 on Mojave: this seems to work fine now. 2) Building WebKit for Mac using Xcode 11 on Mojave: this doesn't work, because of things like bug 199705. The underlying problem seems to be building with the Catalina SDK on a host machine with an older macOS. I believe this is the configuration that's not found on any bot, so is subject to breakage at any time. The easiest way to workaround this would be to keep around an older Xcode and switch to it (using xcode-select) when you want to build WebKit for Mac.
All dependencies fixes so closing.