What to do when you can’t run iOS simulator on Apple Silicon Mac (arm64 binary error)

Depending on the framework incorporated into the application, the following error may occur and prevent the iOS simulator from running on an Apple Silicon Mac.

ld: in /Volumes/Data/src/RK/TechGakuWebSite/SampleCodes/OpenCVTest_iOS/common/opencv2.framework/opencv2(ios_conversions.o), building for iOS Simulator, but linking in object file built for iOS, for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

This example of error output occurs in OpenCV 4.6.0. This article will show you how to deal with it.

Error Cause

When an app was built with arm64 for the iOS simulator on an Apple Silicon Mac, it seems to be due to the fact that the framework for the iOS device was linked to the build for the iOS simulator when the framework incorporated was not fully compatible with Xcode 12 or later architecture or Apple Silicon.

How to deal with it

Apple Silicon Macs have Rosetta2, so binaries built with the x86_64 version can still be used in the iOS simulator and Xcode’s SwiftUI preview.

When building for the iOS simulator, configure it not to build with arm64. Do the following.

STEP

Open the “Build Settings” tab of the app’s target settings.

STEP

Select “Debug” under “Excluded Architectures” in “Architectures”.

STEP

Click the “+” button displayed in the “Debug” row. “Any SDK” will be added.

STEP

Change the added “Any SDK” to “Any iOS Simulator SDK”.

STEP

Enter “arm64” in the “Any iOS Simulator SDK” setting. This will prevent debug builds for the iOS Simulator from building with arm64.

STEP

Do as same as steps (4) and (5) to set arm64 for the “Release” build.