osx builds failing with CMake error

[jtschuster]

Most/all osx builds of the runtime are failing in CI with the following error:

  CMake Error at /Users/runner/work/1/s/eng/native/functions.cmake:668 (add_executable):
    Feature 'RESCAN', specified through generator-expression '$<LINK_GROUP>' to
    link target 'ilasm', is not supported for the 'CXX' link language.
  Call Stack (most recent call first):
    ilasm/CMakeLists.txt:73 (add_executable_clr)
  
  
  CMake Error at /Users/runner/work/1/s/eng/native/functions.cmake:681 (add_library):
    Feature 'RESCAN', specified through generator-expression '$<LINK_GROUP>' to
    link target 'mscordaccore', is not supported for the 'CXX' link language.
  Call Stack (most recent call first):
    dlls/mscordac/CMakeLists.txt:119 (add_library_clr)
  
  
  -- Generating done (4.3s)
  CMake Generate step failed.  Build files cannot be regenerated correctly.
##[error]Failed to generate "CoreCLR component" build project!
##[error]src/coreclr/runtime.proj(120,5): error MSB3073: (NETCORE_ENGINEERING_TELEMETRY=Build) The command ""/Users/runner/work/1/s/src/coreclr/build-runtime.sh" -x64 -release -ci -os osx -ninja -targetrid osx-x64 -cmakeargs "-DCLR_DOTNET_RID=osx-x64" -cmakeargs "-DCLR_DOTNET_HOST_PATH='/Users/runner/work/1/s/.dotnet/dotnet'" -cmakeargs "-DCDAC_BUILD_TOOL_BINARY_PATH=/Users/runner/work/1/s/artifacts/bin/coreclr/osx.x64.Release/cdac-build-tool/cdac-build-tool.dll" -cmakeargs "-DFEATURE_DYNAMIC_CODE_COMPILED=1" " exited with code 1.
/Users/runner/work/1/s/src/coreclr/runtime.proj(120,5): error MSB3073: The command ""/Users/runner/work/1/s/src/coreclr/build-runtime.sh" -x64 -release -ci -os osx -ninja -targetrid osx-x64 -cmakeargs "-DCLR_DOTNET_RID=osx-x64" -cmakeargs "-DCLR_DOTNET_HOST_PATH='/Users/runner/work/1/s/.dotnet/dotnet'" -cmakeargs "-DCDAC_BUILD_TOOL_BINARY_PATH=/Users/runner/work/1/s/artifacts/bin/coreclr/osx.x64.Release/cdac-build-tool/cdac-build-tool.dll" -cmakeargs "-DFEATURE_DYNAMIC_CODE_COMPILED=1" " exited with code 1.

https://dev.azure.com/dnceng-public/public/_build/results?buildId=1341439&view=logs&jobId=1c4513f5-15be-5f8c-3c15-7e4daaa8a0df&j=1c4513f5-15be-5f8c-3c15-7e4daaa8a0df&t=8584d788-56af-5e82-c324-ad34bed6e081
https://dev.azure.com/dnceng-public/public/_build/results?buildId=1341751&view=logs&j=68afeb8a-5f36-53b5-e167-657129fcc990&t=67b49f63-0452-5974-0a23-a88bf58630cb
https://dev.azure.com/dnceng-public/public/_build/results?buildId=1341751&view=logs&j=68afeb8a-5f36-53b5-e167-657129fcc990&t=67b49f63-0452-5974-0a23-a88bf58630cb

Known Issue Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": "Feature 'RESCAN', specified through generator-expression",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1341439
Error message validated: [Feature 'RESCAN', specified through generator-expression]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 3/19/2026 12:26:57 AM UTC

Report

Build	Definition	Step Name	Console log	Pull Request
2930690	dotnet-runtime	Build product	Log
1343162	dotnet/runtime	Build product	Log	#123827
1343117	dotnet/runtime	Build product	Log	#125732
1343104	dotnet/runtime	Build product	Log	#125766
1343107	dotnet/runtime	Build product	Log	#125763
1343112	dotnet/runtime	Build product	Log	#125759
1343097	dotnet/runtime	Build product	Log	#125749
1343077	dotnet/runtime	Build product	Log	#125774
1343080	dotnet/runtime	Build product	Log	#121223
1343074	dotnet/runtime	Build product	Log	#125768
1343024	dotnet/runtime	Build product	Log	#125615
1343013	dotnet/runtime	Build product	Log	#125772
1342983	dotnet/runtime	Build product	Log	#125771
1342756	dotnet/runtime	Build product	Log	#115996
1342968	dotnet/runtime	Build product	Log	#122950
1342966	dotnet/runtime	Build product	Log	#122950
1342965	dotnet/runtime	Build product	Log	#123990
1342937	dotnet/runtime	Build product	Log	#125441
1342934	dotnet/runtime	Build product	Log	#125441
1342908	dotnet/runtime	Build product	Log	#124266
1342879	dotnet/runtime	Build product	Log	#124648
1342884	dotnet/runtime	Build product	Log	#123209
1342882	dotnet/runtime	Build product	Log	#123209
1342891	dotnet/runtime	Build product	Log	#125439
1342887	dotnet/runtime	Build product	Log	#124645
1342881	dotnet/runtime	Build product	Log	#124648
1342876	dotnet/runtime	Build product	Log	#124650
1342878	dotnet/runtime	Build product	Log	#124650
1342866	dotnet/runtime	Build product	Log	#125770
1342868	dotnet/runtime	Build product	Log	#125770
1342852	dotnet/runtime	Build product	Log	#125437
1342854	dotnet/runtime	Build product	Log	#125437
1342834	dotnet/runtime	Build product	Log	#125759
1342837	dotnet/runtime	Build product	Log	#122950
1342821	dotnet/runtime	Build product	Log	#125768
1342810	dotnet/runtime	Build product	Log	#125646
1342812	dotnet/runtime	Build product	Log	#125646
1342798	dotnet/runtime	Build product	Log	#125507
1342794	dotnet/runtime	Build product	Log	#125507
1342759	dotnet/runtime	Build product	Log	#115996
1342725	dotnet/runtime	Build product	Log	#125656
1342727	dotnet/runtime	Build product	Log	#125656
1342717	dotnet/runtime	Build product	Log	#124650
1342647	dotnet/runtime	Build product	Log
1342672	dotnet/runtime	Build product	Log	#125703
1342674	dotnet/runtime	Build product	Log	#125703
1342646	dotnet/runtime	Build product	Log
1342637	dotnet/runtime	Build product	Log	#123209
1342634	dotnet/runtime	Build product	Log	#123209
1342628	dotnet/runtime	Build product	Log	#124647
1342626	dotnet/runtime	Build product	Log	#124647
1342616	dotnet/runtime	Build product	Log	#125766
1342618	dotnet/runtime	Build product	Log	#125766
1342615	dotnet/runtime	Build product	Log	#124650
1342607	dotnet/runtime	Build product	Log	#124646
1342609	dotnet/runtime	Build product	Log	#124646
1342598	dotnet/runtime	Build product	Log	#124648
1342600	dotnet/runtime	Build product	Log	#124648
1342586	dotnet/runtime	Build product	Log
1342581	dotnet/runtime	Build product	Log	#122950
1342414	dotnet/runtime	Build product	Log
1342567	dotnet/runtime	Build product	Log	#125764
1342550	dotnet/runtime	Build product	Log	#125764
1342553	dotnet/runtime	Build product	Log	#125764
1342549	dotnet/runtime	Build product	Log
1342516	dotnet/runtime	Build product	Log	#125764
1342209	dotnet/runtime	Build product	Log	#125758
1341703	dotnet/runtime	Build product	Log	#125710
1341705	dotnet/runtime	Build product	Log	#125710
1342481	dotnet/runtime	Build product	Log	#125507
1342479	dotnet/runtime	Build product	Log	#125507
1342406	dotnet/runtime	Build product	Log	#125670
1342409	dotnet/runtime	Build product	Log	#125670
1342332	dotnet/runtime	Run ILLink Tests	Log	#125762
1342330	dotnet/runtime	Build product	Log	#125762
1342306	dotnet/runtime	Build product	Log	#124716
1342291	dotnet/runtime	Build product	Log	#121223
1342303	dotnet/runtime	Build product	Log	#124716
1342276	dotnet/runtime	Build product	Log	#125761
1342294	dotnet/runtime	Build product	Log	#121223
1342281	dotnet/runtime	Build product	Log	#125761
1342249	dotnet/runtime	Build product	Log	#125759
1342233	dotnet/runtime	Build product	Log	#124738
1342235	dotnet/runtime	Build product	Log	#124738
1342238	dotnet/runtime	Build product	Log
1342207	dotnet/runtime	Build product	Log	#125545
1342205	dotnet/runtime	Build product	Log	#125545
1342158	dotnet/runtime	Build product	Log	#121223
1342151	dotnet/runtime	Build product	Log	#125752
1342153	dotnet/runtime	Build product	Log	#125752
1342077	dotnet/runtime	Build product	Log	#123252
1342056	dotnet/runtime	Build product	Log	#125754
1342052	dotnet/runtime	Build product	Log	#125754
1342045	dotnet/runtime	Build product	Log	#125703
1342043	dotnet/runtime	Build product	Log	#125703
1342036	dotnet/runtime	Build product	Log	#125749
1342010	dotnet/runtime	Build product	Log	#125592
1342034	dotnet/runtime	Build product	Log	#125749
1342007	dotnet/runtime	Build product	Log	#125684
1342009	dotnet/runtime	Build product	Log	#125684
Displaying 100 of 120 results

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
120	120	120

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[jkotas]

@jkoritzinsky Any idea why it started failing out of the blue?

[steveisok]

From what I can tell, https://github.com/actions/runner-images/releases/tag/macos-15%2F20260317.0278 landed yesterday. That had the honor of updating homebrew LLVM to 18 and is the first one NativeAOT and native libs pluck instead of the xcode one.

[jkoritzinsky]

From what I can tell, https://github.com/actions/runner-images/releases/tag/macos-15%2F20260317.0278 landed yesterday. That had the honor of updating homebrew LLVM to 18 and is the first one NativeAOT and native libs pluck instead of the xcode one.

An image update was exactly what I was expecting to be the problem. We're picking up homebrew LLVM's Clang instead of XCode's Clang (and all of our affordances to handle this case are based on identifying AppleClang). We probably need to update our compiler location scripts to explicitly use Xcode when present.

[EgorBo]

I assume

 Undefined symbols for architecture x86_64:
    "__swift_FORCE_LOAD_$_swift_Builtin_float", referenced from:
        __swift_FORCE_LOAD_$_swift_Builtin_float_$_pal_swiftbindings in libSystem.Security.Cryptography.Native.Apple.a(pal_swiftbindings.o)
       (maybe you meant: __swift_FORCE_LOAD_$_swift_Builtin_float_$_pal_swiftbindings)
...
  ld: symbol(s) not found for architecture x86_64
  clang-18: error: linker command failed with exit code 1 (use -v to see invocation)

is also the same issue, but it's not picked up by BA as a know issue

[steveisok]

is also the same issue, but it's not picked up by BA as a know issue

yes