We build TestFlight/App Store builds of our app through Xcode Cloud. Our app uses Metal shaders so we install the Metal toolchain through a ci_pre_xcodebuild.sh script which simply runs:
xcodebuild -downloadComponent metalToolchain
in our Xcode Cloud builds.
This has been working well for us for the last 6 months or so, but since yesterday (March 5) we have been seeing consistent failures when running this script in our Xcode Cloud builds:
Beginning asset download...
2026-03-06 04:14:34.727 xcodebuild[13315:58523] Writing error result bundle to /var/folders/6h/_32gb9js77g6c54h3q7g6q1h0000gn/T/ResultBundle_2026-06-03_04-14-0034.xcresult
xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({
RequestedBuild = 17C7003j;
})
Prior to Mar 5 it looks like the toolchain image which was being downloaded/installed was 17C519 but this has now changed to 17C7003j.
We haven't changed anything with our Xcode Cloud workflow setup, and the same macOS/Xcode images are being used for the workflow runs (macOS Tahoe 26.2 (25C56) and Xcode 26.3 (17C529) respectively) now as when our builds were succeeding a few days ago.
What's the best way to resolve this issue? Looks like we can't even pass an image identifier to xcodebuild -downloadComponent so we're a bit stuck here.
Xcode Cloud
RSS for tagAutomate workflows to test, analyze, build, and distribute your app, and integrate them with other developer tools, such as TestFlight and App Store Connect.
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