I have a C++ project that produces a lot of libraries that require C++20. I have tried to set the requirement for that in the module.modulemap like so (for example): module cxx_library { requires cplusplus20 header "library.h" link "CXXLibrary" } This seems to be correct per the clang documentation: https://clang.llvm.org/docs/Modules.html#requires-declaration However I cannot figure out how to get cmd+click on the imported module in my sample swift file to work with this. For one, Xcode seems to refuse to even import my module when it requires C++20. How do I tell Xcode that all of my C++/ObjectiveC++ requires C++20? The compiler default is C++14, but it's not clear how to properly change that so that I can import a C++20-enabled clang module into some sample swift projects to try out the new interior features. If I remove the 20 from my requires statement, and just use my code as-is, It always complains in the UI that: Couldn't Generate Swift Representation Error (from SourceKit): "Could not load module: cxx_library (could not build Objective-C module 'cxx_library', unknown type name 'char8_t')" Which is very frustrating. When I compile with CMake, I can just set this: add_executable(E E.swift) target_compile_options(E PRIVATE -cxx-interoperability-mode=default SHELL:-Xcc SHELL:-std=c++20) target_link_libraries(E PRIVATE cxx_library) And swiftc compiles the code with no issue. I have uploaded a minimized version of my code as a fork of a project by compnerd on GitHub here: https://github.com/ADKaster/swift-cmake-examples/tree/main/Interop The project builds just fine with cmake -S Interop -B build -GNinja cmake --build build But by creating an Xcode project from it: cmake -S Interop -B build-xcode -GXcode and then opening build-xcode/P.xcodeproj in Xcode 15 Beta, and trying to cmd-click on import cxx_library in E.swift does not work.