Xcode 26.0.1 Seems to be missing Swift Runtime Components

[bdaz]

Description

Running on macOS-15, the Xcode 26.0.1 installation seems to be missing Swift compatibility libraries. This is a regression from the Xcode 26.0 installation, which didn't have these issues.

Warning: ld: search path '/var/run/com.apple.security.cryptexd/mnt/com.apple.MobileAsset.MetalToolchain-v17.1.324.0.uSQZWr/Metal.xctoolchain/usr/lib/swift/iphoneos' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibility50': library 'swiftCompatibility50' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibility51': library 'swiftCompatibility51' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibility56': library 'swiftCompatibility56' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibilityConcurrency': library 'swiftCompatibilityConcurrency' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibilityDynamicReplacements': library 'swiftCompatibilityDynamicReplacements' not found
Warning: ld: Could not find or use auto-linked library 'swiftCompatibilityPacks': library 'swiftCompatibilityPacks' not found
Warning: ld: Could not find or use auto-linked framework 'CoreAudioTypes': framework 'CoreAudioTypes' not found
Warning: ld: Could not find or use auto-linked framework 'UIUtilities': framework 'UIUtilities' not found
Warning: ld: Could not parse or use implicit file '/Applications/Xcode_26.0.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/SwiftUICore.framework/SwiftUICore.tbd': cannot link directly with 'SwiftUICore' because product being built is not an allowed client of it
Error: Undefined symbols for architecture arm64
Error:   "__swift_FORCE_LOAD_$_swiftCompatibility50", referenced from:
Warning:       __swift_FORCE_LOAD_$_swiftCompatibility50_$_FirebaseAnalytics in FirebaseAnalytics[17](Analytics+StoreKit.o)
Error:   "__swift_FORCE_LOAD_$_swiftCompatibility51", referenced from:
Warning:       __swift_FORCE_LOAD_$_swiftCompatibility51_$_FirebaseAnalytics in FirebaseAnalytics[17](Analytics+StoreKit.o)
Error:   "__swift_FORCE_LOAD_$_swiftCompatibility56", referenced from:
Warning:       __swift_FORCE_LOAD_$_swiftCompatibility56_$_FirebaseAnalytics in FirebaseAnalytics[17](Analytics+StoreKit.o)
Error:   "__swift_FORCE_LOAD_$_swiftCompatibilityConcurrency", referenced from:
Warning:       __swift_FORCE_LOAD_$_swiftCompatibilityConcurrency_$_FirebaseAnalytics in FirebaseAnalytics[17](Analytics+StoreKit.o)
Error:   "__swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements", referenced from:
Warning:       __swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements_$_FirebaseAnalytics in FirebaseAnalytics[17](Analytics+StoreKit.o)
Error: ld: symbol(s) not found for architecture arm64
Error: clang: error: linker command failed with exit code 1 (use -v to see invocation)

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26 Arm64
• Windows Server 2019
• Windows Server 2022
• Windows Server 2025

Image version and build link

Image: macos-15-arm64
Version: 20250928.2397

Is it regression?

Yes. Didn't happen with Image: macos-15-arm64 Version: 20250922.2357.

Expected behavior

Swift compatibility libraries should be available, and the linker should not error out

Actual behavior

Linker failure

Repro steps

In this case it's FirebaseAnalytics (latest version) that's first trying to link with the swift compatibility libraries. So build an app that depends on FirebaseAnalytics with a GitHub workflow.

[bdaz]

I'm not sure what the deployment process is for runner images, but this is the doc change for the actual image change I would assume is causing this: #13102

[shamil-mubarakshin]

Hey @bdaz, thanks for bringing this up. There were a few changes to macOS 15 images when going to 20250928.2397 which I would like to test.
While coming up with the FirebaseAnalytics based app for repro would take some time, providing a sample project could speed things up

[lxr-mwhite]

I have a very similar issue that also started when the macOS-15 build agent was updated with Xcode 26.0.1.

INFO [2025-10-06 19:45:51.83]: ▸ ⚠️ ld: search path '/Users/runner/Library/Developer/DVTDownloads/MetalToolchain/mounts/4ab058bc1c53034b8c0a9baca6fba2d2b78bb965/Metal.xctoolchain/usr/lib/swift/iphoneos' not found
INFO [2025-10-06 19:45:51.83]: ▸ ⚠️ ld: Could not find or use auto-linked library 'swiftCompatibility56': library 'swiftCompatibility56' not found
INFO [2025-10-06 19:45:51.83]: ▸ ⚠️ ld: Could not find or use auto-linked library 'swiftCompatibilityPacks': library 'swiftCompatibilityPacks' not found
INFO [2025-10-06 19:45:51.83]: ▸ ⚠️ ld: Could not find or use auto-linked framework 'UIUtilities': framework 'UIUtilities' not found
INFO [2025-10-06 19:45:51.83]: ▸ ⚠️ ld: Could not parse or use implicit file '/Applications/Xcode_26.0.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/SwiftUICore.framework/SwiftUICore.tbd': cannot link directly with 'SwiftUICore' because product being built is not an allowed client of it
INFO [2025-10-06 19:45:51.83]: ▸ ❌ Undefined symbols for architecture arm64
INFO [2025-10-06 19:45:51.83]: ▸ ❌   "__swift_FORCE_LOAD_$_swiftCompatibility56", referenced from:
INFO [2025-10-06 19:45:51.83]: ▸ ⚠️       __swift_FORCE_LOAD_$_swiftCompatibility56_$_FirebaseCoreInternal in libFirebaseCoreInternal.a[3](_ObjC_HeartbeatController.o)
INFO [2025-10-06 19:45:51.83]: ▸ ❌ ld: symbol(s) not found for architecture arm64
INFO [2025-10-06 19:45:51.83]: ▸ ❌ clang: error: linker command failed with exit code 1 (use -v to see invocation)

This issue doesn't happen on my own MacBook when using Xcode 26.0.1.

@shamil-mubarakshin Not sure if the following build task would help identify if something was missed or changed during the Xcode update but adding this task to my build pipeline before building my iOS app resulted in a successful build.

- script: |
    set -e
    TOOLCHAIN="$(xcode-select -p)/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphoneos"
    SDK="$(xcrun --sdk iphoneos --show-sdk-path)/usr/lib/swift"

    echo "Restoring Swift compatibility libs with symlink if needed..."
    if [ -f "$TOOLCHAIN/libswiftCompatibility56.a" ]; then
      echo "✅ Found libswiftCompatibility56.a in toolchain"
      if [ ! -f "$SDK/libswiftCompatibility56.tbd" ] && [ ! -f "$SDK/libswiftCompatibility56.a" ]; then
        echo "⚡ Creating symlink in SDK path"
        ln -s "$TOOLCHAIN/libswiftCompatibility56.a" "$SDK/libswiftCompatibility56.a"
      else
        echo "Already present in SDK path"
      fi
    else
      echo "❌ libswiftCompatibility56.a not found in toolchain"
    fi

    echo "Final SDK contents:"
    ls -l "$SDK" | grep Compatibility || echo "No Compatibility libs found in SDK"
  displayName: "Symlink Swift Compatibility56 Library"

@bdaz If you haven't found a workaround for your issue yet, maybe this can help in the meantime? Just ensure that Xcode 26.0.1 is selected before you run this task. Or if you did find a workaround, can you please share what your solution is?

--EDIT--
Update: I am working on two different projects and one of them does not have this issue despite being built with the same Xcode version and Firebase dependencies + versions. I suspect it may be a project setting discrepancy that I will look into further and provide updates if I find anything.

[bdaz]

@lxr-mwhite Thanks! That approach worked for me after generalizing to work for a number of swift compatibility libraries:

- name: Fix Missing Swift Compatibility Libraries
        run: |
          set -euo pipefail

          TOOLCHAIN="$(xcode-select -p)/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphoneos"
          SDK="$(xcrun --sdk iphoneos --show-sdk-path)/usr/lib/swift"

          echo "🔧 Restoring missing Swift Compatibility libraries if needed..."
          echo "Toolchain path: $TOOLCHAIN"
          echo "SDK path:       $SDK"

          # List of possible compatibility libraries to restore
          LIBS=(
            libswiftCompatibility50.a
            libswiftCompatibility51.a
            libswiftCompatibility56.a
            libswiftCompatibilityConcurrency.a
            libswiftCompatibilityDynamicReplacements.a
            libswiftCompatibilityPacks.a
          )

          for LIB in "${LIBS[@]}"; do
            TOOLCHAIN_LIB="$TOOLCHAIN/$LIB"
            SDK_LIB_A="$SDK/$LIB"
            SDK_LIB_TBD="${SDK_LIB_A%.a}.tbd"

            if [ -f "$TOOLCHAIN_LIB" ]; then
              if [ ! -f "$SDK_LIB_A" ] && [ ! -f "$SDK_LIB_TBD" ]; then
                echo "⚡ Creating symlink for $LIB"
                ln -s "$TOOLCHAIN_LIB" "$SDK_LIB_A"
              else
                echo "✅ $LIB already exists in SDK"
              fi
            else
              echo "⚠️ $LIB not found in toolchain"
            fi
          done

          echo ""
          echo "🧩 Final Swift SDK contents:"
          ls -l "$SDK" | grep Compatibility || echo "No Compatibility libs found."

          echo ""
          echo "Checking for missing Apple frameworks..."
          SYSFWK="$(xcrun --sdk iphoneos --show-sdk-path)/System/Library/Frameworks"
          for FWK in CoreAudioTypes UIUtilities; do
            if [ ! -d "$SYSFWK/$FWK.framework" ]; then
              echo "⚠️ Framework $FWK not found in $SYSFWK"
            else
              echo "✅ Framework $FWK found"
            fi
          done

          echo ""
          echo "Swift compatibility library repair complete."

Fair warning: I didn't generalize this, ChatGPT did. But it worked for me.

@shamil-mubarakshin Appreciate you looking into this. Hopefully the above workaround is helpful context. Would be great to ditch the hack above when we can.

I've attached a sample project that has FirebaseAnalytics as a Cocoapod dependency, which is what I suspect is sufficient to break the Github action when it tries to build it.

(@lxr-mwhite are you using Cocoapods out of curiosity?)

SwiftCompatibilityLibTest.zip

[lxr-mwhite]

@bdaz Yes I am using CocoaPods in a React Native project that uses Firebase. I'm working on two different apps which are both using the same versions of Firebase dependencies. I haven't figured out yet why one appears to work as is but the other needs this workaround.

[lxr-mwhite]

@bdaz Do your logs have a few extra lines above and below the ones you shared that may identify any of your classes?
On my end I figured out the issue, but it doesn't necessarily mean it should be the accepted solution. But I did mention earlier that I have one project that works and one that started failing on Xcode 26.0.1.

Both of my projects have a NotificationService extension, but the issue for me was that the failing project's NotificationService was still in Objective-C. I've converted it to Swift and now I don't have issues with the build.

[bdaz]

@lxr-mwhite None of my own classes are identified in the logs, no. Just FirebaseAnalytics. Worth noting though, I have a huge amount of Objective-C in my app. It's probably 90%+ ObjC.

[netog-ppb]

Having the same issue, the build:

• Works with mac 15 + Xcode 16.4
• Works with mac 26 + Xcode 16.4 (Same runner image that breaks on Xcode 26.0.1)
• Works with mac 26 + Xcode 26.0.0 (Previous runner image, no longer available)
• Breaks with mac 15 + Xcode 26.0.1
• Breaks with mac 26 + Xcode 26.0.1
• Breaks with mac 26 + Xcode 26.1.0-beta

Locally my build works just fine with Mac 15 + Xcode 26.0.1

[shamil-mubarakshin]

@bdaz, thanks for the provided sample, I was able to build and reproduce the issue, but manually linking libraries suggested here didn't work me. I also didn't find noticeable difference in TOOLCHAIN and SDK folder contents for Xcode 16.4 and Xcode 26.0.1.
After some investigations, I am leaning towards changes introduced by MetalToolchain addition #13088 for Xcode 26.*, which was requested by some users a few weeks back.
Removing assets downloaded by xcodebuild -downloadComponent MetalToolchain workarounds the issue in my case:

    - name: Try metalToolchain cleanup
      run: |
        sudo rm -rf /System/Library/AssetsV2/com_apple_MobileAsset_MetalToolchain

I will dig around more to see if we should introduce fixes to the image and will appreciate your inputs as well