In the end I removed the project, did a clean checkout from git, and now it works again 🤷‍♂️

This issue is driving me nuts. And for me it happens literally every time I plug in my iPhone. Unplug, plug it back in, wait 5 minutes for Xcode to make the watch ready for development. Which then usually (but not always) fails by the way! Plug it back in, and you're just stuck waiting for 5 minutes yet again. When it fails, I get this error: Unable to prepare iPhone for development Could not locate the device support files. But building an app to my iPhone still works 🤷‍♂️

Running into the same issue (and filed a bug report: FB7652731). Everything is setup correctly, everything works on iOS: I am sharing builds with a select group of (external) testers. Now I have added macOS support as well, and am trying to share a build with my testers. However, since there is no TestFlight for macOS apps, and sharing it using the Developer ID is broken, I am only left with an actual release to the Mac App Store? I am not ready for that yet.So is there simply no way at the moment to share a macOS app, using Sign In with Apple, to a select group of people?