No Xcode builds on CI

In the process of trying to figure out this error (Clang: error: unknown argument: '-fswift-async-fp=always') I noticed that CI doesn't appear to be doing any Xcode builds. Are we testing the --xcode flag anywhere? I'd like to compare to a known-good setup to see what might be causing the issue in the linked thread.


I know is a work around, but commenting this command swift/CMakeLists.txt at 78809726080ce61a4f73c013d542c91d5da35f2e · apple/swift · GitHub should make you able to build with --xcode locally.

The issue on the thread is caused by a flag introduced on clang that is passed on build to compile Concurrency C/C++ code. This works without --Xcode because the version of clang selected is the one built from source with those changes applied. But for Xcode clang version selected is the pre-built one shipped with Xcode itself which still doesn't have this flag available. So once Xcode ships with the version of clang that supports this flag it will not be a problem. I've spent some time looking into this trying to see if there was a way to force Xcode build to link against built from source clang, but couldn't do it due limited knowledge in that area :sweat_smile:
and the workaround was enough to unblock the local build for sometime.

1 Like