cmake on Mac with ARM M1 is running linker with x86_64 architecture instead of arm64

Question

I am trying to compile glfw from source on Mac with M1 arm64 processor, and while running the linker, cmake strangely is trying to link the project for x86_64 architecture, while the binaries were built for arm64.

I clone the project, create build folder named cmake-build-debug, generate build system in it with the Makefile etc. as follows:

git clone https://github.com/glfw/glfw.git
cd glfw
mkdir cmake-build-debug
cd cmake-build-debug
cmake -S .. -B . -DCMAKE_BUILD_TYPE=Debug -DCMAKE_HOST_SYSTEM_PROCESSOR=arm64 -DCMAKE_SYSTEM_PROCESSOR=arm64

This works fine. But now that I build it with make or cmake --config Debug --build ., the .o binaries are generated perfectly fine, but linker script is incorrectly invoked by cmake with x86_64 target architecture for some reason:

-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- Including Cocoa support
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/burkov/Documents/Projects/open-source/glfw/cmake-build-debug
[ 47%] Built target glfw
Scanning dependencies of target wave
[ 50%] Linking C executable wave.app/Contents/MacOS/wave
ld: warning: ignoring file CMakeFiles/wave.dir/wave.c.o, building for macOS-x86_64 but attempting to link with file built for unknown-arm64
ld: warning: ignoring file ../src/libglfw3.a, building for macOS-x86_64 but attempting to link with file built for macOS-arm64
Undefined symbols for architecture x86_64:
  "_main", referenced from:
     implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [examples/wave.app/Contents/MacOS/wave] Error 1
make[1]: *** [examples/CMakeFiles/wave.dir/all] Error 2
make: *** [all] Error 2

I look at the failing Makefile in glfw/cmake-build-debug/examples/CMakeFiles/wave.dir/build.make and see the line, where cmake is crashing:

cd /Users/me/Documents/Projects/open-source/glfw/cmake-build-debug/examples && $(CMAKE_COMMAND) -E cmake_link_script CMakeFiles/wave.dir/link.txt --verbose=$(VERBOSE)

I manually open the file glfw/cmake-build-debug/examples/CMakeFiles/wave.dir/link.txt file and see the following link script code there:

/Library/Developer/CommandLineTools/usr/bin/cc -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names  CMakeFiles/wave.dir/wave.c.o  -o wave.app/Contents/MacOS/wave  ../src/libglfw3.a -framework Cocoa -framework IOKit -framework CoreFoundation 

If I manually execute this line from shell, it successfully builds my binary for arm64 architecture, as expected.

But when this link.txt script is automatically invoked with cmake via cmake -E cmake_link_script CMakeFiles/wave.dir/link.txt --verbose=$(VERBOSE), it fails, apparently, trying to build the binary for the wrong x86_64 architecture.

Why is this happening and how to fix this?

Answer 1

For anyone running into the same problem, it looks like the first version of cmake with an adequate support for Apple Silicon is 3.19.

I was using 3.17.5 as my slightly out-of-date version of CLion does not support versions of cmake above that.

After an update to cmake 3.22.4 the problem is gone.