Building from source with XCode 11.7 fails

[rorbech]

Building the project from source with XCode 11.7 fails with

> Task :cinterop:capiMacosUniversal FAILED
-- The C compiler identification is AppleClang 11.0.3.11030032
-- The CXX compiler identification is AppleClang 11.0.3.11030032
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc - broken
CMake Error at /Applications/CMake.app/Contents/share/cmake-3.18/Modules/CMakeTestCCompiler.cmake:66 (message):
  The C compiler

    "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /Users/claus.rorbech/proj/realm-kotlin/packages/external/core/capi_macos_universal/CMakeFiles/CMakeTmp
    
    Run Build Command(s):/usr/local/bin/gmake cmTC_0a618/fast && /usr/local/bin/gmake  -f CMakeFiles/cmTC_0a618.dir/build.make CMakeFiles/cmTC_0a618.dir/build
    gmake[1]: Entering directory '/Users/claus.rorbech/proj/realm-kotlin/packages/external/core/capi_macos_universal/CMakeFiles/CMakeTmp'
    Building C object CMakeFiles/cmTC_0a618.dir/testCCompiler.c.o
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc   -arch x86_64 -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9 -o CMakeFiles/cmTC_0a618.dir/testCCompiler.c.o -c /Users/claus.rorbech/proj/realm-kotlin/packages/external/core/capi_macos_universal/CMakeFiles/CMakeTmp/testCCompiler.c
    Linking C executable cmTC_0a618
    /Applications/CMake.app/Contents/bin/cmake -E cmake_link_script CMakeFiles/cmTC_0a618.dir/link.txt --verbose=1
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc  -arch x86_64 -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9 -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/cmTC_0a618.dir/testCCompiler.c.o -o cmTC_0a618 
    ld: warning: ignoring file /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/lib/darwin/libclang_rt.osx.a, missing required architecture arm64 in file /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.3/lib/darwin/libclang_rt.osx.a (3 slices)
    ld: warning: ignoring file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/lib/libSystem.tbd, missing required architecture arm64 in file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/lib/libSystem.tbd
    ld: dynamic main executables must link with libSystem.dylib for architecture arm64
    clang: error: linker command failed with exit code 1 (use -v to see invocation)
    gmake[1]: *** [CMakeFiles/cmTC_0a618.dir/build.make:106: cmTC_0a618] Error 1
    gmake[1]: Leaving directory '/Users/claus.rorbech/proj/realm-kotlin/packages/external/core/capi_macos_universal/CMakeFiles/CMakeTmp'
    gmake: *** [Makefile:140: cmTC_0a618/fast] Error 2

Immediate workaround is to remove "-DOSX_ARM64=1" argument in https://github.com/realm/realm-kotlin/blob/master/packages/cinterop/build.gradle.kts#L323

[rorbech]

Closing as outdated