I'm developing an audio unit for use on iOS. The AUv3 worked fine with xcode 15.X and swift 5.X. I recently tried to submit an update to my plug-in but Apple refused submission because my Xcode was not the latest. Now that I'm on Xcode 16.4 I can't get my project to compile, even when following all of the same previous steps.
As one example of a change, Xcode doesn't appear to include the “C++ and Objective-C interoperability” build setting that it used to. This setting is noted in the Swift documentation and I used to need it, https://www.swift.org/documentation/cxx-interop/project-build-setup/#mixing-swift-and-c-using-xcode
Currently my C++ code can't see anything from Swift, and I get a "Use of undeclared identifier 'project_name'". I've selected Switch support for version 5.0 in an attempt to minimize changes from Apple.
My process is I generate an Xcode project file from my audio plugin support, JUCE. Then I add in the swift files, click yes to create bridging headers, but c++ doesn't see swift anymore. I'd greatly appreciate any suggestions.
So I tried restarting from the backup of my last working version. I recompiled module Swift stuff and this time my main project was able to compile! Yay! (Of course right after I post here). I have no idea what is different about this older project file than a new one.