build disappears

I can confirm the behavior and want to add the developer perspective. I build an app that uses Apple’s on-device Foundation Models (with a Core ML fallback). When the device UI is set to Catalan, Apple Intelligence is disabled, so the Foundation Models APIs report unavailable. This blocks my app from handling prompts in English or Spanish even when the user explicitly selects those languages in-app. Developer impact • I must ship separate code paths and degrade features based on UI language, not user intent. • Users who prefer a Catalan UI lose on-device, privacy-preserving LLM features, so I am forced to route to cloud or third-party SDKs. • QA complexity rises because availability hinges on language toggles and reboots, as the bug report here illustrates. Repro (app context) 1. Set iPhone language to Catalan. 2. Call Foundation Models API from the app. availability reports not available. 3. Switch device language to Spanish. Availability often remains “unavailable” until reboot. 4. After reboot, av

The exact same problem is also triggered through SwiftUI's ColorPicker(), when supportsOpacity is set to false. As with the original post, the issue is with macOS 26.0 and Xcode 26.0.1 when building a macOS app.

I can compile and run the project but I cannot use previews with Xcode 26.0.1. My projects needs to have use legacy previews execution switch enabled otherwise all previews are crashing during initialisation for same strange reason I have given up looking for a solution. With Xcode 26.0.1 the automatic build executed for legacy previews always fails with this error message so now I'm not able to use previews at all.

Ok, so as a workaround, we can remove all the *.usdz's from the RealityContent rkassets folder (and import them using Entity(named: from the main bundle). But then , for the remaining 50kb of RealityContent.rkassets folder with a few shader graph materials, we get many minutes of build time 😳

Thanks for your post. I was wondering if you have a way to reproduce the issue. Do you get the same results with just the relevant code in a small test project? If so, please share a link to your test project. That'll help us better understand what's going on. If you're not familiar with preparing a test project, take a look at Creating a test project. A focused Xcode project that builds and demonstrates the issue. Ideally this will be a new Xcode project created specifically to demonstrate this issue, and which includes only the minimal code and API necessary to reproduce the issue. This focuses on the important code paths and may require you to perform additional debugging to extract the relevant code. Please do not include any 3rd-party code or frameworks unless they are absolutely required for this targeted test project to run. We also recommend adding appropriate logging to your focused project. See Technical Note TN2347 - Basic debugging with the NSLog function and the DEBUG preprocessor macro:

Anyone know if it's going to be this way going forward? I get it that a lot of ppl don't need the tool chain, thus making it optional. But I feel like the runners in xcode cloud should have this installed by default Each build adds 5+ minutes just to download&install it. I'm actually considering having a prebuilt metallib in the repo if this will be the case going forward.

I encountered this issue this morning. In my case I had the build set to use Latest Beta or Release and swapping it to Latest Release cleared the issue up. That's obviously not an option if you need the beta build to develop against upcoming APIs, but if you had it set that way and no longer need the latest beta it's worth a try.

Steps to reproduce: create default Xcode ARKit RealityKit template app open Reality Composer Pro, create new project, choose a folder somewhere in the above created app add RealityKitContent as dependency under Frameworks, Libraries, and Embedded Content drag the example Usdz into the reality composer project, maybe add it to base scene setup Xcode cloud basic build Result would be the above error. Additionally it always takes > 2min to fail: If I remove the *.usdz file it works (so it's not like the metal toolchain isn't installed or realitytool not working) Here's the example file, I shared it via dropbox since I can't attach usdz's here. It's just the monkey head from blender exported as usdz and crushed using usdcrush https://www.dropbox.com/scl/fi/f7b7dsyspby1zabk26932/monkey_crushed.usdz?rlkey=feilrul7gx6naxkbun7oaezv0&st=8afj5ewt&dl=0

Running the mentioned command, I still get the same error: iOS 23A339 is not available for download. ec2-user@ip-XX-XX-XX-XX ~ % xcversion selected Xcode 26.0 Build version 17A324 ec2-user@ip-XX-XX-XX-XX ~ % xcodebuild -downloadPlatform iOS -exportPath ~/Downloads -buildVersion 23A339 Finding content... iOS 23A339 is not available for download.