(*) The package to add back /usr/include currently does not exist in 10.15 beta, so unless it reappears come final release this is going to be more of a problem there….This package is not going to be coming back: https://developer.apple.com/documentation/xcode_release_notes/xcode_10_release_notes#3035623
Indeed, it is not at all unexpected to no longer have this option with Xcode 11.
