Hello community,
After unable to use Metal Toolchain for Xcode Beta 1 and 2 even after following the workarounds, and using Xcode Beta 3, I am still unable to use the downloaded Metal Compiler on my device.
Building any project with metal file results in
warning: Could not read serialized diagnostics file: error("Failed to open diagnostics file") (in target '<target>' from project '<project>')
error: error: cannot execute tool 'metal' due to missing Metal Toolchain; use: xcodebuild -downloadComponent MetalToolchain
Command CompileMetalFile failed with a nonzero exit code
Here is my build environment,
$ xcodebuild -version
Xcode 26.0
Build version 17A5276g
I have also checked the downloaded metal toolchain.
$ xcodebuild -downloadComponent metalToolchain -exportPath /tmp/MyMetalExport/
2025-07-13 13:16:17.293 xcodebuild[2153:34019] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it.
Beginning asset download...
2025-07-13 13:16:17.427 xcodebuild[2153:34022] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it.
Downloaded asset to: /System/Library/AssetsV2/com_apple_MobileAsset_MetalToolchain/47af11e2964f385d510c6a9d1a49c8165f334a51.asset/AssetData/Restore/022-19457-052.dmg
Beginning asset export...
Done exporting: /tmp/MyMetalExport/MetalToolchain-17A5276g.exportedBundle
Done downloading: Metal Toolchain 17A5276g.
The ExportMetadata.plist has a buildUpdateVersion of 17A5276g.
Any suggestions are greatly appreciated.