./bootstrap-vcpkg.sh on mac selects wrong compiler

[autoantwort]

Describe the bug
When I run ./bootstrap-vcpkg.sh I get the following error:

➜  vcpkg git:(fix-meson) ✗ ./bootstrap-vcpkg.sh                                                         
Downloading vcpkg tool sources
Building vcpkg-tool...
-- The CXX compiler identification is GNU 11.2.0
-- Checking whether CXX compiler has -isysroot
-- Checking whether CXX compiler has -isysroot - yes
-- Checking whether CXX compiler supports OSX deployment target flag
-- Checking whether CXX compiler supports OSX deployment target flag - yes
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Check for working CXX compiler: /usr/local/bin/g++-11
-- Check for working CXX compiler: /usr/local/bin/g++-11 - broken
CMake Error at /Users/leanderSchulten/git_projekte/Lichtsteuerung/vcpkg/downloads/tools/cmake-3.20.2-osx/cmake-3.20.2-macos-universal/CMake.app/Contents/share/cmake-3.20/Modules/CMakeTestCXXCompiler.cmake:59 (message):
  The C++ compiler

    "/usr/local/bin/g++-11"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /Users/leanderSchulten/git_projekte/Lichtsteuerung/vcpkg/buildtrees/_vcpkg/build/CMakeFiles/CMakeTmp
    
    Run Build Command(s):/Users/leanderSchulten/git_projekte/Lichtsteuerung/vcpkg/downloads/tools/ninja-1.10.2-osx/ninja cmTC_3da22 && [1/2] Building CXX object CMakeFiles/cmTC_3da22.dir/testCXXCompiler.cxx.o
    FAILED: CMakeFiles/cmTC_3da22.dir/testCXXCompiler.cxx.o 
    /usr/local/bin/g++-11   -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk -o CMakeFiles/cmTC_3da22.dir/testCXXCompiler.cxx.o -c testCXXCompiler.cxx
    g++-11: error: this compiler does not support arm64
    ninja: build stopped: subcommand failed.

  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt:33 (project)


-- Configuring incomplete, errors occurred!
See also "/Users/leanderSchulten/git_projekte/Lichtsteuerung/vcpkg/buildtrees/_vcpkg/build/CMakeFiles/CMakeOutput.log".
See also "/Users/leanderSchulten/git_projekte/Lichtsteuerung/vcpkg/buildtrees/_vcpkg/build/CMakeFiles/CMakeError.log".

I can workaround this by passing the option -allowAppleClang to the script, but it should autoselect clang on arm macs or on macOS >= 10.15(?)

Environment

• OS: macOS 11 with Apple M1

Expected behavior
It should simply compile vcpkg

[NancyLi1013]

Hi @autoantwort

Thanks for posting this issue.

vcpkg will choose gcc as the default compiler to build on Unix platform. So if you want to use clang compiler, you need to pass the option -allowAppleClang to build.

[autoantwort]

So if you want to use clang compiler, you need to pass the option -allowAppleClang to build.

Yeah I know, but that must be the default on arm macs. Or do you think that getting this error as default behavior is a good thing?

Btw this is not a question, it is a vcpkg-bug ;)

[JackBoosY]

gcc bug, see iains/gcc-darwin-arm64#35.

[autoantwort]

Yeah, but until then vcpkg bootstrap fails