Thanks for the reply, but this is still a very puzzling issue.
I just installed the latest Xcode beta 6, and then created a fresh plugin project with Projucer. When I try to build it, it immediately dies in the preprocessor, so it doesn’t even make it to the point where I can see the command line and more detailed error listing.
As you can see in the image, Xcode complains that it can’t find any JUCE code in <> brackets. This applies to every .mm and .cpp file in the JUCE Library Code folder in my project.
So far as I can tell, my Header Search Paths looks correct…it should be able to find the JUCE modules.
As I’ve said, this works perfectly with Xcode 9.4.1. My only guesses as to why this seems to be only affect me is that my JUCE folder and project are in a Dropbox folder, although it doesn’t affect anything else. Somehow Xcode 10 is handling header search paths differently than Xcode 9?
Anything help or clues here would be greatly appreciated. Thanks.