What is the proper way to build for macOS-x86_64 using cmake on Apple M1 (arm)?

Question

I'm using a library that I cannot compile for Apple M1, so I have decided to compile it and use it using (Rosetta 2) for x86_64 which I successfully did following this to install brew and clang for x86_64.

However when I compile my project and try to link it against this library I get this error:

ld: warning: ignoring file ..../libapronxx.a, building for macOS-arm64 but attempting to link with file built for macOS-x86_64
...
ld: symbol(s) not found for architecture arm64

I have tried to the set compiler and linker flags ("-arch x86_64") but still got the same problem.

My question is: What is the proper way to build for macOS-x86_64 using cmake on Apple M1 (arm)?

Additional information: I'm using cmake via CLion.

UPDATE: I successfully compiled my project using the following commands:

# install a x86 cmake
arch -x86_64 /usr/local/bin/brew install cmake
...
# in the build directory
arch -x86_64 /usr/local/bin/cmake ..
make
arch -x86_64 ./my_exe

I also specified the architecture for clang using -arch flag

string(APPEND CMAKE_CXX_FLAGS_RELEASE " -arch x86_64 -O3")
string(APPEND CMAKE_CC_FLAGS_RELEASE " -arch x86_64 -O3")
# did the same for debug too

While this work fine, I still don't believe it is the proper way to use cmake to build for macOS-x86_64, in fact I cannot take the advantages of my IDE with all this manual approach.

Answer 1

After checking CMake source code, I found that it is enough to set CMAKE_OSX_ARCHITECTURES to x86_64:

set(CMAKE_OSX_ARCHITECTURES "x86_64")

This is the cleanest way so far to solve this issue, and work straight forward with CLion too.