The clang compiler does not support '-march=native'

[retoc71586]

Good evening everyone. I am trying to install the project on my m1 Mac. I managed to install all of the requirements but running ./build.sh it doesn't work. I repetitively get the same error: the clang compiler does not support '-march=native' which results in:

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)

[retoc71586]

I managed to go a little further by substituting this flag in the CMakeList.txt file everywhere by: -mcpu=apple-m1. However now when building I get 2 kind of errors: 1st of the kind fatal error: 'something.h' file not found 2nd 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) or similarly ld: warning: ignoring file something.o, building for macOS-x86_64 but attempting to link with file built for unknown-arm64 Undefined symbols for architecture x86_64:

[retoc71586]

For the first kind of errors let me be more specific. From my understanding They come from the fact that clang++ compiler can not use libstdc++. The first problem I had was with stdint-gcc.h and I could solve it just by replacing it with<stdint.h> Then I had problems with boost: I have downloaded it trough home-brew but clang still couldn’t find it so I edited the CMakeList.txt files to include /usr/local/include path:

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}  -I/opt/local/include -Wall  -O3 -mcpu=apple-m1 ")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/opt/local/include -Wall  -O3 -mcpu=apple-m1")

Lastly the compiler couldn't find tr1/whatever so I got rid of tr1/ and just left whatever and it compiled successfully

However I am still getting the linking errors in all three the thirdparty packages and I am not sure how to fix this

[retoc71586]

I want to be a little more clear on the architecture errors I am getting because I narrowed them down to two occurrences:

1) The first time they appear is after [100%] Linking CXX shared library ../lib/libDBoW2.dylib, in Scanning dependencies of target DBoW2. They are all related to my opencv installation and raise errors of this kind: ld: warning: ignoring file /opt/anaconda3/envs/3D-vision-project/lib/libopencv_gapi.4.5.5.dylib, building for macOS-arm64 but attempting to link with file built for macOS-x86_64 However I am pretty sure I have installed the arm64 packages, directly trough conda with the command conda install -c conda-forge opencv.

2) The second time when they occur is after Build files have been written to: path_to_orbslam3/ORB_SLAM3/Thirdparty/Sophus/build: I still get the ld: warning: ignoring file CMakeFiles/test_common.dir/test_common.cpp.o, building for macOS-x86_64 but attempting to link with file built for unknown-arm64 kind of errors (NB this time it tries to build for macOS-x86_64 which is wrong, it should go for macOS-arm64 and I don't know where can I force this). However here there is also a more serious issue: 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]: *** [test/core/test_common] Error 1 make[1]: *** [test/core/CMakeFiles/test_common.dir/all] Error 2

I hope I have been clear enough for someone to give me some help with the building procedure

[retoc71586]

I have managed to get the Sophus build to work by downloading a different CMakeLists.txt file from the sops GitHub and modifying it a little. The only problem left is with the build of DBoW2. I do not know why but the linker looks for x86 libraries when I have downloaded the arm64 trough conda install -c conda-forge opencv

[papasega]

Hello You can change : -march=native by -mcpu=apple-m1

[mccharley]

Have you tried export SYSTEM_VERSION_COMPAT=1? used here to address a similar issue with the compiler

[Qucy]

Have you tried export SYSTEM_VERSION_COMPAT=1? used here to address a similar issue with the compiler

Thanks, this work for my Mac.