Question

Xcode12 CoreNFC simulator library not loaded

Our app uses CoreNFC to scan NFC tags or you can use QR if NFC is not supported. This worked pretty well and we were able to run the app in the simulator for (ui) testing purposes.
Until Xcode12 / iOS14 GM builds. In iOS13 (or lower) we wouldn't have any issues running it on a simulator.

But in Xcode12 running it on a iOS14 simulator iPhone11 we would get the following:

dyld: launch, loading dependent libraries
DYLD_SHARED_CACHE_DIR=/Users/xxx/Library/Developer/CoreSimulator/Caches/dyld/19G73/com.apple.CoreSimulator.SimRuntime.iOS-14-0.18A372
DYLD_ROOT_PATH=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot
DYLD_LIBRARY_PATH=/Users/xxx/Library/Developer/Xcode/DerivedData/xxx-awnlestrbvesqqbynrhmluzhbcsc/Build/Products/Debug-iphonesimulator:/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/introspection
DYLD_INSERT_LIBRARIES=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libBacktraceRecording.dylib:/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSi
dyld: Library not loaded: /usr/lib/libnfshared.dylib
  Referenced from: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/CoreNFC.framework/CoreNFC
  Reason: no suitable image found.  Did find:
    /usr/lib/libnfshared.dylib: mach-o, but not built for platform iOS-sim

That the simulator crashes makes sense to me, since the simulator can't scan NFC tags, but this is what I've done:

I already linked to the CoreNFC framework and made it optional, like described here: Xcode 10, Swift 4 app with CoreNFC crashes in review on iOS 12
Put #if canImport(CoreNFC) around import CoreNFC and it's underlying NFC code.
Cleaning the build folder and deleting derived data.
Created an empty Xcode12 project: https://github.com/basvankuijck/CoreNFCCrashProject, same result.
Removed all the listed simulators and re-added one
Added -weak_framework "CoreNFC" to the Other Linker Flags build setting

Obviously removing any references to the CoreNFC framework by either commenting out code sections and removing the framework link, makes the crash disappear. But that's not a suitable option.

Running it from Xcode12 on an iOS13 simulator 'device' works perfectly. So I can't seem to figure out what is causing this behavior

48 8883 48

1 Jan 1970

Solution

Apple obviously forgot to add libnfshared.dylib for whatever reason in the final version of Xcode 12 for iOS 14 simulators. A working workaround until Apple fixes this is to copy the missing lib from Xcode 12 beta 6 over (download the beta from Apple's developer download section). The missing lib can be found here and must go into the same directory for final Xcode 12

This works for me.

If you want to avoid the hassle of downloading 11.25GB Xcode 12.2 beta for a single file. I have the file to share.

You may execute the following command to download and place it inside the Xcode package:

sudo curl https://storage.googleapis.com/mobile-simulator-build/libnfshared.dylib -o /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libnfshared.dylib

2020-10-01

Solution

Apple obviously forgot to add libnfshared.dylib for whatever reason in the final version of Xcode 12 for iOS 14 simulators. A working workaround until Apple fixes this is to copy the missing lib from Xcode 12 beta 6 over (download the beta from Apple's developer download section). The missing lib can be found here and must go into the same directory for final Xcode 12:

Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/usr/lib

2020-09-22