The reply from aliwang is correct, and solved this problem for me right away. My Build Settings supported language was set to 'objective-c / objective-c++' and the framework project simply would not build. How on earth in 2024 Apple has not been able to make Xcode interop C/C++/Obj-C/Swift out of the box is beyond me. Since all of these languages are a superset of C. You know many of us want this, you guys use it yourself more and more. Just work it into Xcode and be done with it already.

Solved: The issue was the factoryFunction description in both the info.plist file and .exp file - ensure your factoryFunction is written so it includes the same class name as your AudioUnit subclass followed the word 'Function', eg: info.plist file = AUSubClassFunction. .exp file = _AUSubClassFunction See Apple Technical Doc here for clarification: https://developer.apple.com/library/archive/technotes/tn2276/_index.html

I was having this same issue today when running auval on a newly developed template project - I found this article mentioning the same error bring thrown by auval (dyld: warning, LC_RPATH @executable_path/../Frameworks ...) https://betterprogramming.pub/create-audio-unit-extension-from-scratch-77abee79d12 The fix worked for me, passing all auval tests now, and the test project loading in Logic as expected. Change Framework install path from from default "@executable_path" to "@loader_path" inside Build Setting / Linking.