debugpy exits due to Xfrozen_modules

[ssooffiiaannee]

Environment data

• debugpy version: 1.8.16
• OS and version: ubuntu 24.04
• Python version : 3.12
• Using VS Code or Visual Studio: vs code

Actual behavior

python -Xfrozen_modules=off -m debugpy --wait-for-client --listen 5675 ../poky/bitbake/bin/bitbake busybox
0.00s - Debugger warning: It seems that frozen modules are being used, which may
0.00s - make the debugger miss breakpoints. Please pass -Xfrozen_modules=off
0.00s - to python to disable frozen modules.
0.00s - Note: Debugging will proceed. Set PYDEVD_DISABLE_FILE_VALIDATION=1 to disable this validation.

Expected behavior

skip frozen_module and not exit the debugger

Steps to reproduce:

clone poky
source poky/oe-init-build-env
python -Xfrozen_modules=off -m debugpy --wait-for-client --listen 5675 ../poky/bitbake/bin/bitbake busybox
run debugger in vscode

[rchiodo]

I don't think that's causing the app to exit. It's just a warning. What actually happens when you run the python command?

[ssooffiiaannee]

IT exited because it hit an "os.execl" syscall inside a daemon function. Not a debugpy issue I suppose.

Is it possible to debug daemons run with os.execl?
I have added the following to the daemon script, it is not breaking nor binding to the vscode client :

import debugpy 

# Listen on a port for VSCode to attach
debugpy.listen(("0.0.0.0", 5678))
debugpy.wait_for_client()

[ssooffiiaannee]

After investigating, I figured out that for some reason the process running os.execl disconnects from the debugger, and adding debugpy.listen iniside the script and connecting throws something like "process with pid is already being debugged".
DOes debugpy support debugging of deamon started with os.execl ?

[rchiodo]

I don't think this use case is supported. AFAICT, os.execl restarts the python runtime with the same pid?

So debugpy shuts down (when the python runtime stops) but then the client still thinks it's debugging the same process.

[ssooffiiaannee]

yes os.execl start the runtime with the same pid.
subprocesses that run os.execl cannot be debugged along with parent processes, either parents or children that exec os.execl, not both at the same time.