[Discourse.ros.org] [Next Generation ROS/Troubleshooting] Import error No module named 'rclpy._rclpy' cross compiling
I am _cross compiling_ ros2 beta2 for a ARM platform. I get the source `. ./setup.sh` done and after I try to launch the python talker but `rclpy._rclpy` cannot be imported. The default Python version is Python 3.5.
The talker written with C++ works perfect.
I also tried to update the `rclpy` repo to the latest version, and I am getting the same error.
Traceback (most recent call last):
File "/opt/ros2/lib/demo_nodes_py/talker", line 9, in <module>
load_entry_point('demo-nodes-py==0.0.0', 'console_scripts', 'talker')()
File "/usr/lib/python3.5/site-packages/setuptools-22.0.5-py3.5.egg/pkg_resources/__init__.py", line 542, in load_entry_point
File "/usr/lib/python3.5/site-packages/setuptools-22.0.5-py3.5.egg/pkg_resources/__init__.py", line 2569, in load_entry_point
File "/usr/lib/python3.5/site-packages/setuptools-22.0.5-py3.5.egg/pkg_resources/__init__.py", line 2229, in load
File "/usr/lib/python3.5/site-packages/setuptools-22.0.5-py3.5.egg/pkg_resources/__init__.py", line 2235, in resolve
File "/opt/ros2/lib/python3.5/site-packages/topics/talker.py", line 18, in <module>
File "/opt/ros2/lib/python3.5/site-packages/rclpy/__init__.py", line 18, in <module>
from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
File "/opt/ros2/lib/python3.5/site-packages/rclpy/impl/implementation_singleton.py", line 32, in <module>
rclpy_implementation = importlib.import_module('._rclpy', package='rclpy')
File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
ImportError: No module named 'rclpy._rclpy'
I have noticed that are similar errors at Windows platform.
@LanderU can you please open an issue on the [rclpy repository](https://github.com/ros2/rclpy/) with all the information regarding your setup and your install ?
Regarding cross-compilation, sorry @abilbaotm for missing this thread. AFAIK we haven't tried to cross-compile the Python stack. The logic of the python imports has changes quite a bit since beta2 so the situation may be different today. If you happen to be willing to give it another shot and report here with the details of how you defined and linked against your targets' python libraries that would be helpful.
In the meantime for ARM users we do provide ros2 debs for aarch64 on repo.ros2.org and nightly aarch64 builds [here](http://ci.ros2.org/view/packaging/job/packaging_linux-aarch64/lastSuccessfulBuild/artifact/).