Build Fails for Raspberry Pi 4 B: libcaffe2.so: undefined reference to `__atomic_xxx_8'

[BeibinLi]

Raspberry Pi 4 Model B (4 GB RAM version).
Python 3.7.3
Architecture: armv7l

Settings:
NO_MLKDNN=1
NO_CUDA=1
NO_QNNPACK=1
NO_NNPACK=1
NO_DISTRIBUTED=1
python3 setup.py build

========================================
The last few lines for the results:

[ 71%] Building CXX object caffe2/CMakeFiles/caffe2.dir/transforms/pattern_net_transform.cc.o
[ 72%] Building CXX object caffe2/CMakeFiles/caffe2.dir/transforms/single_op_transform.cc.o
[ 72%] Linking CXX shared library ../lib/libcaffe2.so
[ 72%] Built target caffe2
Scanning dependencies of target caffe2_pybind11_state
Scanning dependencies of target pattern_net_transform_test
[ 72%] Building CXX object caffe2/CMakeFiles/pattern_net_transform_test.dir/transforms/pattern_net_transform_test.cc.o
[ 72%] Building CXX object caffe2/CMakeFiles/caffe2_pybind11_state.dir/python/pybind_state.cc.o
[ 72%] Linking CXX executable ../bin/pattern_net_transform_test
/usr/bin/ld: /home/pi/pytorch/build/lib/libcaffe2.so: undefined reference to __atomic_fetch_add_8' /usr/bin/ld: /home/pi/pytorch/build/lib/libcaffe2.so: undefined reference to __atomic_load_8'
/usr/bin/ld: /home/pi/pytorch/build/lib/libcaffe2.so: undefined reference to __atomic_exchange_8' /usr/bin/ld: /home/pi/pytorch/build/lib/libcaffe2.so: undefined reference to __atomic_fetch_sub_8'
/usr/bin/ld: /home/pi/pytorch/build/lib/libcaffe2.so: undefined reference to `__atomic_compare_exchange_8'
collect2: error: ld returned 1 exit status
make[2]: *** [caffe2/CMakeFiles/pattern_net_transform_test.dir/build.make:88: bin/pattern_net_transform_test] Error 1
make[1]: *** [CMakeFiles/Makefile2:2058: caffe2/CMakeFiles/pattern_net_transform_test.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 72%] Building CXX object caffe2/CMakeFiles/caffe2_pybind11_state.dir/python/pybind_state_dlpack.cc.o
[ 72%] Building CXX object caffe2/CMakeFiles/caffe2_pybind11_state.dir/python/pybind_state_nomni.cc.o
[ 72%] Building CXX object caffe2/CMakeFiles/caffe2_pybind11_state.dir/python/pybind_state_registry.cc.o
[ 72%] Linking CXX shared module python/caffe2_pybind11_state.cpython-37m-arm-linux-gnueabihf.so
[ 72%] Built target caffe2_pybind11_state
make: *** [Makefile:141: all] Error 2
Failed to run 'bash ../tools/build_pytorch_libs.sh caffe2'
pi@raspberrypi:~/pytorch $

[BeibinLi]

I spent a whole day and resolved this issue by the following steps:

1. sudo apt-get install libatomics-ops-dev
2. Change CMAKE_CXX_FLAGS variable in CMakeLists.txt file (in the main directory). i.e. add line set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -latomic")

I also uploaded the torch 1.0.0 .whl file if anyone needs it: https://drive.google.com/file/d/1D3A5YSWiY-EnRWzWbzSqvj4YdY90wuXq/view?usp=sharing

[coriolan-v]

Hi @BeibinLi, thanks for the info, can you share a copy of you CMakeLists.txt file?
How exactly do you change the CMAKE_CXX_FLAGS variable and add the file?

[JiahanLiu]

Here's a 1.3 Pytorch Wheel and 0.4.1 vision for armv7l (Raspberry Pi 4 tested):

https://github.com/JiahanLiu/JiahanLiuThesis/blob/master/RaspberryPi4/torch-1.3.0a0%2Bde394b6-cp37-cp37m-linux_armv7l.whl
https://github.com/JiahanLiu/LocalGlobalFedLearning/blob/master/RaspberryPi4/torchvision-0.4.1a0%2Ba263704-cp37-cp37m-linux_armv7l.whl

Like @SArham said below to download it using wget change "blobl" in the URL to "raw"

[SArham]

Thanks @JiahanLiu

For downloading with wget. Changed blob to raw in the url.

https://github.com/JiahanLiu/JiahanLiuThesis/raw/master/RaspberryPi4/torch-1.3.0a0%2Bde394b6-cp37-cp37m-linux_armv7l.whl

@coriolan-cs Via your terminal, go to the pytorch folder.
copy and paste this command
sed -i '/set(CMAKE_EXPORT_COMPILE_COMMANDS ON)/a set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -latomic")' CMakeLists.txt
Additionally, try LD_PRELOAD=</usr/lib/arm-linux-*/libatomic.so.x.y> python setup.py build

This gives priority to this specific library version for building.

This same problem happens with mxnet on the raspberry pi too.

[jrcichra]

I spent a whole day and resolved this issue by the following steps:

1. sudo apt-get install libatomics-ops-dev
2. Change CMAKE_CXX_FLAGS variable in CMakeLists.txt file (in the main directory). i.e. add line set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -latomic")

I also uploaded the torch 1.0.0 .whl file if anyone needs it: https://drive.google.com/file/d/1D3A5YSWiY-EnRWzWbzSqvj4YdY90wuXq/view?usp=sharing

For me it was libatomic-ops-dev on a raspberry pi 4