I have Sonoma and Xcode 15 installed. Both Xcode and the simulator are extremely slow. CPU usage is very high. I can load up a simple App in the simulator after some waiting. SwiftUI Preview will keep the CPU at 70% usage but sometimes it crashes. I have a Intel CPU so I am not sure if this is a x86 specific issue.

I got the same issue in all Xcode 14 releases. Tried delete account and add new one back but doesn't work.

I finally got rid of the error messages by changing my modulemap file from "extern_c" to "system" module ABC [system] { ... }

Defect #61104 raised but I am still not able to work around the issue at the moment.

I am also getting this for a c library wrapper project. Interestingly the Build succeeded even with a bunch of errors like below. Rebuild project with Xcode 14 didn't fix my problem :( Dependency for P1:target-SwiftSMB-f940fa9bfd7461b6bfd7a1821b88923283a44e681aeb1f425a9cef51a7a8aacb-:Debug:SwiftDriver Compilation Requirements SwiftSMB normal x86_64 com.apple.xcode.tools.swift.compiler is not absolute (libsmb2/include/smb2/smb2.h). ... Showing All Errors Only Command SwiftDriver Compilation Requirements emitted errors but did not return a nonzero exit code to indicate failure