Build failed on macOS Sonoma with Xcode 15: zig2 duplicate symbol `__mh_execute_header`

[thelastlin]

Zig Version

0.11.0

Steps to Reproduce and Observed Behavior

1. Install required dependencies.
2. Configure and build with:

   export SDKROOT=$(xcrun --sdk macosx --show-sdk-path); cd builld;
   cmake .. -DCMAKE_PREFIX_PATH=$PATH_TO_LLVM16_INSTALL_PATH
   make -j`nproc`

   which SDKROOT will be set to /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.0.sdk
3. Failed at Linking CXX executable zig2, linker output:

    @(#)PROGRAM:ld  PROJECT:dyld-1015.7
    BUILD 19:43:18 Aug 22 2023
    configured to support archs: armv6 armv7 armv7s arm64 arm64e arm64_32 i386 x86_64 x86_64h armv6m armv7k armv7m armv7em
    will use ld-classic for: armv6 armv7 armv7s arm64_32 i386 armv6m armv7k armv7m armv7em
    LTO support using: LLVM version 15.0.0 (static support for 29, runtime is 29)
    TAPI support using: Apple TAPI version 15.0.0 (tapi-1500.0.12.3)
    Library search paths:
        ... 
    Framework search paths:
    ld: warning: ignoring duplicate libraries: '/path/to/llvm-16/lib/libclangAST.a', '/path/to/llvm-16/lib/libclangASTMatchers.a', '/path/to/llvm-16/lib/libclangAnalysis.a', '/path/to/llvm-16/lib/libclangParse.a', '/path/to/llvm-16/lib/libclangSema.a', '/path/to/llvm-16/lib/libclangStaticAnalyzerCheckers.a', '/path/to/llvm-16/lib/libclangStaticAnalyzerCore.a', '/path/to/llvm-16/lib/libclangStaticAnalyzerFrontend.a'
    duplicate symbol '__mh_execute_header' in:
        /path/to/build/CMakeFiles/zig2.dir/zig2.c.o
        boundary-file
    ld: 1 duplicate symbols
   

---

macOS: 23A5337a
Xcode: 15A5229m
LLVM(llvm-config --version): 16.0.6

Expected Behavior

1. Succeed in linking zig2.

[jedisct1]

As a quick workaround, edit zig2.c and remove the definition:

struct mach_header_64__3906 _mh_execute_header = {UINT32_C(0xaaaaaaaa), ... };

[mikdusan]

Further hint, this is definitely triggered when Xcode 15 (Release Candidate) linker is used, even on Ventura. It looks like the latest system linker is more strict.

[mikdusan]

another hint

• zig2.c declares without weak attribution
• zig (stage3) when build-obj a main.zig file declares with weak attribution

but what's going on here? If we look as to why the symbol is used... it's used when .zig owns (exports) main. It's not needed when .c owns main. And this is further re-enforced by your workaround.

I'm thinking when backend is .c we have 2 choices:

1. do not define _mh_execute_header
2. define _mh_execute_header but it must be weak

[jvo203]

This problem is happening on the latest macOS Ventura 13.6 too, M1 Ultra chip, even with the latest zig (after "git pull"). Can't compile / build zig.