The XCode 13 RC release notes do mention following in the preview section: Previews ... Deprecations Xcode 13 no longer includes a menu item in the Previews canvas for debugging a preview. Instead, use the Debug > Attach to Process menu item to attach the debugger to your previewed app. (73981969) However, there are no instructions anywhere on how to find the process to attach to. I tried attaching to XCPreviewAgent process that seems to be spawned when I switch into run mode. Only to be hit by permission failures to debug.

Unfortunately this is a bug that must be fixed in XCode. Here are some more discussions regarding the same: https://github.com/pointfreeco/swift-composable-architecture/discussions/581 with some solutions that work for sometimes.

I have submitted https://feedbackassistant.apple.com/feedback/9118422 for this