undefined symbol: __atomic_exchange_8 - python-3.x

Question

I'm trying to run google assistant on my raspberry pi following the steps on: https://developers.google.com/assistant/sdk/guides/service/python/embed/run-sample
all works fine until activating the Google Assistant with the command:
googlesamples-assistant-pushtotalk --project-id my-dev-project --device-model-id my-model
I'm getting the following ImportError:
Traceback (most recent call last):
File "/home/pi/env/bin/googlesamples-assistant-pushtotalk", line 5, in <module>
from googlesamples.assistant.grpc.pushtotalk import main
File "/home/pi/env/lib/python3.9/site-packages/googlesamples/assistant/grpc/pushtotalk.py", line 28, in <module>
import grpc
File "/home/pi/env/lib/python3.9/site-packages/grpc/__init__.py", line 22, in <module>
from grpc import _compression
File "/home/pi/env/lib/python3.9/site-packages/grpc/_compression.py", line 15, in <module>
from grpc._cython import cygrpc
ImportError: /home/pi/env/lib/python3.9/site-packages/grpc/_cython/cygrpc.cpython-39-arm-linux-gnueabihf.so: undefined symbol: __atomic_exchange_8
Any ideas on how to fix this?

Answer 1

just ended up here since I ran into the same problem (on a different project) but also involving python3.9, cygrpc on a RPi4 with a recent raspbian-lite (32bit).
While I don't have a solution here are my guesses:
formerly __atomic_exchange_8 was defined in /lib/arm-linux-gnueabihf/libgcc_s.so.1 but now it seems defined in libatomic:
$ grep __atomic_exchange_8 /lib/arm-linux-gnueabihf/libatomic.so.1
grep: /lib/arm-linux-gnueabihf/libatomic.so.1: binary file matches
EDIT:
Solved it. I was looking at the patch which tried to solve the problem two years ago:
https://github.com/grpc/grpc/pull/20514/commits/b912fc7d8d401bb65b3147ee77d03beaa3d46038
I figured their test check_linker_need_libatomic() might be broken, and patched it again to always return True, the problem got fixed.
Had tried earlier to fix it by adding CFLAGS='-latomic' CPPFLAGS='-latomic' but that didn't help.
here's my tiny workaround (not fix!) for today's grpc git HEAD:
root#mypi:/home/pi/CODE/grpc# git diff
diff --git a/setup.py b/setup.py
index 1a72c5c668..60b7705cd2 100644
--- a/setup.py
+++ b/setup.py
## -197,6 +197,7 ## ENABLE_DOCUMENTATION_BUILD = _env_bool_value(
def check_linker_need_libatomic():
"""Test if linker on system needs libatomic."""
+ return True
code_test = (b'#include <atomic>\n' +
b'int main() { return std::atomic<int64_t>{}; }')
cxx = os.environ.get('CXX', 'c++')
diff --git a/tools/distrib/python/grpcio_tools/setup.py b/tools/distrib/python/grpcio_tools/setup.py
index 6b842f56b9..8d5f581ac7 100644
--- a/tools/distrib/python/grpcio_tools/setup.py
+++ b/tools/distrib/python/grpcio_tools/setup.py
## -85,6 +85,7 ## BUILD_WITH_STATIC_LIBSTDCXX = _env_bool_value(
def check_linker_need_libatomic():
"""Test if linker on system needs libatomic."""
+ return True
code_test = (b'#include <atomic>\n' +
b'int main() { return std::atomic<int64_t>{}; }')
cxx = os.environ.get('CXX', 'c++')
root#mypi:/home/pi/CODE/grpc#
EDIT:
as a quick test, cygrpc.cpython-39-arm-linux-gnueabihf.so needs to depend on libatomic:
pi#mypi:~/CODE/grpc $ ldd /usr/local/lib/python3.9/dist-packages/grpc/_cython/cygrpc.cpython-39-arm-linux-gnueabihf.so
linux-vdso.so.1 (0xbeef7000)
/usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0xb698b000)
libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb695f000)
libatomic.so.1 => /lib/arm-linux-gnueabihf/libatomic.so.1 (0xb6946000)
libstdc++.so.6 => /lib/arm-linux-gnueabihf/libstdc++.so.6 (0xb67be000)
libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0xb674f000)
libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb65fb000)
/lib/ld-linux-armhf.so.3 (0xb6fcc000)
libgcc_s.so.1 => /lib/arm-linux-gnueabihf/libgcc_s.so.1 (0xb65ce000)

Answer 2

This works for me on RPI0 + Bullseye + Python3.9:
pip3 uninstall -y grpcio grpcio-tools
sudo apt install -y python3-grpcio python3-grpc-tools

Answer 3

EDIT: Update to gRPC v1.44.0. The issue has been fixed there, see the explanation below in the old answer.
There was a problem with the order of the parameters used by the compiler to compile some test code which result is used to determine whether libatomic needs to be linked or not.
The issue will be fixed with the next release of grpc. If they maintain the same schedule of previous releases it should be v1.44.0 which should come out some time the next month.
In the mean time you can git cherry-pick the proper fix and build grpc yourself