[EXTERNAL] Python kernel with C# cell doesn't execute with C# kernel

[Xarkam]

Describe the bug

Can't execute C# code into ipynb file in vscode stable. But with jupyter-lab I can:

Please complete the following:

Which version of .NET Interactive are you using? There are a few ways to find this out:
1.0.215204

• In a notebook, run the #!about magic command.
  Nothing, just say 0.6s
  
  

• At the command line, run dotnet interactive --version.
  1.0.215204+974732778592b69c526648c54ef4c48219058e97

• OS
  • Windows 10
  • macOS
  • Linux KDE Neon
  • iOS
  • Android
• Browser
  • Chrome
  • Edge
  • Firefox
  • Safari
• Frontend
  • Jupyter Notebook
  • Jupyter Lab
  • nteract
  • Visual Studio Code
  • Other (please specify)

Screenshots

Linux Distribution

[colombod]

What extension do you have? It seems that the code is sent to a python kernel. Despite the language selected in the cell can you verify that you are using the .NET Interactive kernel by using the command palette and then start looking for the choose kernel command?

[Xarkam]

Hi,
That's right, despite the choice of .NET Interactive, it is positioned on python.

[colombod]

How are you opening the notebook?

[colombod]

@brettfo do you have any suggestion?

[Xarkam]

How are you opening the notebook?

How I'm opening ? Tutorial https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.dotnet-interactive-vscode
I just follow the indications of the "doc"

[colombod]

can you check if the the settings for your extension look like this?

[Xarkam]

Not checked by default on my installation.

Edit: On each new notebook, if I select .NET Interactive for a block of code, the active kernel not switch to .NET Interactive

[jonsequitur]

You typically have to select the kernel before the language chooser will work correctly. The experience is still awkward there.

If you're still seeing output from Python instead of .NET, try opening the VS Code command palette, select View: Reopen Editor With..., and select .NET Interactive for Jupyter.

[Xarkam]

You typically have to select the kernel before the language chooser will work correctly. The experience is still awkward there.

If you're still seeing output from Python instead of .NET, try opening the VS Code command palette, select View: Reopen Editor With..., and select .NET Interactive for Jupyter.

Thank you. So while waiting for the experience to become satisfactory, wouldn't it be wise to add a section in the doc for this kind of problem?

[brettfo]

This has been a major point of confusion for users in the past.

The issue appears to be that the Python kernel was selected for the notebook, but the individual cell's language was set to "C# (.NET Interactive)" so editor language services were getting routed to C# appropriately, but cell execution was honoring the kernel.

There are two related issues open against the Jupyter extension, microsoft/vscode-jupyter#4510 and microsoft/vscode-jupyter#4490 that call out how a kernel can (and should?) restrict it's language list, so the Python kernel should ideally not list C# as a possible language.