Since Xcode 27.2, ahead-of-time compiling a Core AI model for an iPhone chip crashes as soon as any part of the model is placed on the Neural Engine: xcrun coreai-build compile Model.aimodel --platform iOS --min-deployment-version 27.0 \ --architecture h17p --preferred-compute neural-engine --output outcoreai-build exits with Segmentation fault: 11 (status 139), prints nothing and writes no output. The crash report points into the Neural Engine compiler: ANEHostCompiler ZinIrCompilerParameters::PropogateGlobalOptionsToPerProcedureOptions(...) ANEHostCompiler ANECompilerOffline::CompileAllTargetProcedures()What we found: It affects every A-series architecture (h16p, h17p, h18p, h19p). M-series targets (h13g through h17g) compile fine. It doesn't depend on the model. A model with a single convolution crashes too. It happens with Xcode 27.2 and 27.3 beta 1. Xcode 27.1 compiles the same models. Models that 27.2 places entirely on the GPU do compile. The Xcode 27.1 toolchain doesn't run on macOS 27.2. It fails at launch with dyld: Symbol not found: … AIModelAsset.delegatesFolderURL(artifactName:). So on macOS 27.2, we currently can't compile Core AI models for an iPhone's Neural Engine at all. The only working setup we have is Xcode 27.1 on macOS 27.0. Reported as FB25501691, with a minimal model and crash reports. Has anyone else run into this or found a workaround?

coreai-build crashes for A-series Neural Engine targets since Xcode 27.2

Since Xcode 27.2, ahead-of-time compiling a Core AI model for an iPhone chip crashes as soon as any part of the model is placed on the Neural Engine:

xcrun coreai-build compile Model.aimodel --platform iOS --min-deployment-version 27.0 \
    --architecture h17p --preferred-compute neural-engine --output out

coreai-build exits with Segmentation fault: 11 (status 139), prints nothing and writes no output. The crash report points into the Neural Engine compiler:

ANEHostCompiler  ZinIrCompilerParameters::PropogateGlobalOptionsToPerProcedureOptions(...)
ANEHostCompiler  ANECompilerOffline::CompileAllTargetProcedures()

What we found:

It affects every A-series architecture (h16p, h17p, h18p, h19p). M-series targets (h13g through h17g) compile fine.
It doesn't depend on the model. A model with a single convolution crashes too.
It happens with Xcode 27.2 and 27.3 beta 1. Xcode 27.1 compiles the same models.
Models that 27.2 places entirely on the GPU do compile.
The Xcode 27.1 toolchain doesn't run on macOS 27.2. It fails at launch with dyld: Symbol not found: … AIModelAsset.delegatesFolderURL(artifactName:).

So on macOS 27.2, we currently can't compile Core AI models for an iPhone's Neural Engine at all. The only working setup we have is Xcode 27.1 on macOS 27.0.

Reported as FB25501691, with a minimal model and crash reports.

Has anyone else run into this or found a workaround?