Design Discussion: Debugging Compiled Python

[ranchhandrobotics]

The ROS extension leverages the Python extension under the covers, with special understanding of the ROS environment (well, mostly) it is running in. However, Colcon builds compiled python without debug symbols.

"Attach" to python was a hold over from the ROS 1 version of the extension - which worked because python wasn't compiled. However, Attach has never worked on ROS 2. Unless I'm missing something - we can't get blood from a rock - or in this case make a compiled python ROS node debuggable after the fact.

I've contemplated solutions to this:

• Removing attach all together
• Providing a prompt that informs about this scenario
• Attempts to introspect to see if it is compiled, has symbols and likely to succeed

How would you solve this?

[Mike-Sagiri]

I notice that --symlink-install may not compile python code, since it just create a soft link to the source python code. And with --symlink-install, the "launch" mode of the extension works. So is it possible to attach if compile with --symlink-install?

[ranchhandrobotics]

That's a great observation, thank you! I'll dig into that more and see if we can detect that case

[Mike-Sagiri]

That's a great observation, thank you! I'll dig into that more and see if we can detect that case

Here's some references.

1. https://www.youtube.com/watch?v=LDAM9aoDe4g
2. https://docs.ros.org/en/humble/How-To-Guides/ROS-2-IDEs.html
   And I wonder if anyone has successfully attached to a ros2 node with / without debugpy, like this issue: [bug] Debug configuration not able to attach to ROS2 node or launch it ms-iot/vscode-ros#813, since I can run debugpy to attach a running python node, but the log of this extension shows that the extension fails to run debugpy. See my issue: [feature] Attach to running Python node fails rde-ros-2#278