I'm trying to setup a macOS 26 build environment in a VM (using UTM and the virtualization framework Apple provides). I have Xcode 26 installed and have logged into my Apple ID and verified that the team and other configuration looks fine in Xcode settings. When trying to build the macOS app, I see errors saying the VM's device ID has not been registered. I have confirmed that the device ID is registered both in the Provisioning portal AND the downloaded .provisionprofiles (in Library > Developer > Xcode > UserData). This problem appears on multiple targets (e.g. the main app and extensions). If I try to manually provision the app, using the Provisioning portal, I can build the product, but it will not launch because of Gatekeeper issues. Finally, signing to run locally doesn't work either. As the app launches, frameworks refuse to load because Team IDs don't match. With ad hoc provisioning, there are no Team IDs. I've come to the conclusion that this just isn't possible. Which is a shame because I need to support products with a build environment on macOS 15 and cannot move over to macOS 26 yet. I suspect many developers outside of Apple are in a similar position.