Debugging doesn't work in Jupyter notebooks

[johnl800]

Debugging doesn't work in Jupyter notebooks - the breakpoints are ignored.

Debugging works with a normal .py file.

VS Code and all of my extensions are up to date.
I'm running Windows 10. I don't think the Python version matters: I've recently updated to 3.12, I think I was running 3.8 when I first noticed it.

Please fix this.

[rchiodo]

Thanks for the issue but we're going to need more information.

It works for me:

Did you try with a simple notebook? How did you start the debugger?

[rchiodo]

It might also be a path mapping issue. Are you doing this remotely? (Breakpoint binding is dependent upon the debugger understanding that the source you're stepping through actually matches the file where the breakpoint is)

[johnl800]

I'm not sure what you mean by simple notebook, the file extension is .ipynb.

I started the debugger from the run menu.

The file is saved locally.

I just tried disabling other Jupyter related extensions, but that didn't help. I notice that when the cell runs (after loading the kernel) the break point changes from a red dot to a white doughnut.

[rchiodo]

By simple notebook I mean something that just has a couple of print statements, and not something that's calling into say other functions defined in other cells or python files.

By run menu, I assume you mean this?

The jupyter extension has to be enabled for this to work (it's the one that sends the necessary commands to the debugger).

What's your version of the jupyter extension?

[rchiodo]

If you set this to debug:

The jupyter output log will show all of the conversions it does for debugging.

For example, I have output like so:

14:00:31.669 [debug] [Debug] to kernel: {"command":"setBreakpoints","arguments":{"source":{"name":"test_notebook.ipynb","path":"vscode-notebook-cell:/c%3A/Users/~/source/testing/test_pylance/test_notebook.ipynb#W3sZmlsZQ%3D%3D"},"lines":[4],"breakpoints":[{"line":4}],"sourceModified":false},"type":"request","seq":6}

14:00:31.669 [debug] [Debug] to kernel, mapped: {"command":"setBreakpoints","arguments":{"source":{"name":"test_notebook.ipynb","path":"C:\\Users\\~\\AppData\\Local\\Temp\\ipykernel_34764\\2104655547.py"},"lines":[4],"breakpoints":[{"line":4}],"sourceModified":false},"type":"request","seq":6}

Which is how debugpy is told what cell your breakpoint is in.

The second message actually shows where debugpy expects to find the source. You can check that file to see what it has in it.