Attaching a VSCode Debugger to a Sub Process in Python

Question

I have a script that effectively does the following:

top_script.py:

os.system("bash_script.sh")

bash_script.sh

python3 child_script.py

child_script.py

# Actual work goes here

In VSCode, I love the integrated debugger, but when I follow their advice[1] when launching from the IDE, I get "ECONNREFUSED 127.0.0.1:5678".

When I execute the following from the integrated terminal in VSCode, it runs without the errors, but it doesn't stop on breakpoints in child_script.py.

python3 -m debugpy --listen 5678 top_script.py

How can I execute the top script first (either from the IDE or command line) and have breakpoints I attach in child_script.py be rendered in VSCode?

[1] https://code.visualstudio.com/docs/python/debugging

Answer 1

You can add a configuration to your launch.json file like the following:

{
        "name": "MySubProcess",
        "type": "python",
        "request": "attach",
        "processId": "${command:pickProcess}"
}

Now start your python process separately (via a prompt, or however). This will generate a python subprocess. You can see this in Windows Task Manager (or also in MacOS Activity monitor, or in Linux a similar way).

In VSCode, then click Debug, (select your subprocess configuration: "MySubProcess" in our example above), and then choose the process which was just started. The debugger will then stop at the breakpoints in your subprocess code.