Start of rosbridge.js aborts (librcl.so not found)

[whatis777]

When trying to start ros2-web-bridge with node bin/rosbridge.js, it aborts with this error message:

/home/ubuntu/webbridgetest/ros2-web-bridge/node_modules/bindings/bindings.js:121
        throw e;
        ^
Error: librcl.so: cannot open shared object file: No such file or directory
    at Object.Module._extensions..node (internal/modules/cjs/loader.js:1057:18)
    at Module.load (internal/modules/cjs/loader.js:863:32)
    at Function.Module._load (internal/modules/cjs/loader.js:708:14)
    at Module.require (internal/modules/cjs/loader.js:887:19)
    at require (internal/modules/cjs/helpers.js:74:18)
    at bindings (/home/ubuntu/webbridgetest/ros2-web-bridge/node_modules/bindings/bindings.js:112:48)
    at Object.<anonymous> (/home/ubuntu/webbridgetest/ros2-web-bridge/node_modules/rclnodejs/lib/clock.js:17:38)
    at Module._compile (internal/modules/cjs/loader.js:999:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
    at Module.load (internal/modules/cjs/loader.js:863:32)

The setup is:

• Ubuntu Server 20.04.1 LTS
• python 3.8.5
• ROS2 Foxy Fitzroy following these instructions
• ros2-web-bridge 0.3.0
• nodejs 12.20.0
• npm 6.14.8
• hardware: raspberry pi 3 B v1.2

librcl.so is located in /opt/ros/foxy/lib:
-rw-r--r-- 1 root root 223912 Dec 10 11:48 librcl.so

echo $LD_LIBRARY_PATH prints
/opt/ros/foxy/opt/yaml_cpp_vendor/lib:/opt/ros/foxy/lib/aarch64-linux-gnu:/opt/ros/foxy/lib

The terminals are sourced by default (echo "source /opt/ros/foxy/setup.bash" >> ~/.bashrc)

ros2-web-bridge was installed in a directory besides the ROS2 workspace using these commands to install it:

git clone https://github.com/RobotWebTools/ros2-web-bridge.git
cd ros2-web-bridge
git checkout 0.3.0
npm install

Can you please help me here?

[minggangw]

It seems that everything has been set properly, normally this kind of issue was caused by not sourcing the setup.bash for ROS2. Can you run the examples of rclpy?

[whatis777]

I have a python-based custom node up & running properly & publishing ROS2 messages if that helps.
If not please let me know which example I should run

[minggangw]

I just want to confirm whether the librcl.so could be found because rclpy is similar to rclnodejs by wrapping the librcl.so library. Currently, I have no idea what causes it, but I suggest you could try to use https://github.com/ros2/ros2/releases/download/release-foxy-20201211/ros2-foxy-20201211-linux-focal-arm64.tar.bz2 package to see if it works.

[whatis777]

1. I did a ROS2 reinstall using the binary and this tutorial
2. reboot
3. Tested the talker & listener nodes as described in the tutorial: both work
4. reinstall ros2-web-bridge (performing the steps as described above)

Performing npm install already shows a similar error at the end of the build:

....
....
make: Leaving directory '/home/ubuntu/webbridgetest/ros2-web-bridge/node_modules/rclnodejs/build'
> [email protected] postinstall /home/ubuntu/webbridgetest/ros2-web-bridge/node_modules/rclnodejs
> node scripts/generate_messages.js
Start JavaScript message generation...
Caught error: Error: librcl.so: cannot open shared object file: No such file or directory
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@~2.1.1 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"arm64"})
added 414 packages from 318 contributors and audited 415 packages in 396.636s

The file is there and the path is known:

• LD_LIBRARY_PATH=/home/ubuntu/ros2_foxy/ros2-linux/opt/yaml_cpp_vendor/lib:/home/ubuntu/ros2_foxy/ros2-linux/opt/rviz_ogre_vendor/lib:/home/ubuntu/ros2_foxy/ros2-linux/lib
• -rw-r--r-- 1 ubuntu ubuntu 829216 Dec 11 19:05 /home/ubuntu/ros2_foxy/ros2-linux/lib/librcl.so