{connection_file} argument not passed to Jupyter kernel

[taisbak]

Similar, but maybe not the same as issue #7063 Kernelspecs with non-default arguments don't work.

Environment data

• VS Code version: 1.60.0-insider (user setup)
• Jupyter Extension version (available under the Extensions sidebar): 2021.8.2028630014
• Python Extension version (available under the Extensions sidebar): 2021.9.1144093763-dev
• OS (Windows | Mac | Linux distro) and version: Windows 10.0.18363
• Python and/or Anaconda version: python: 3.8.11 / miniconda 4.10.3
• Type of virtual environment used: N/A
• Jupyter server running: Local
• Jupyter kernel: Ganimede 1.1.0.20210614 (Java 16)

Expected behaviour

• Connect to Ganimede kernel and execute notebook code - this works when running the notebook using the anaconda provided jupyter notebook application.

Actual behaviour

• Connection fails
• Error 2021-08-19 14:24:55: Failed to connect raw kernel session: Error: Connection file not found in kernelspec json args, C:\Program Files\AdoptOpenJDK\jdk-16.0.1.9-hotspot\bin\java.exe --illegal-access=permit --add-opens java.base/jdk.internal.misc=ALL-UNNAMED -jar C:\Users...\AppData\Roaming\jupyter\kernels\ganymede-1.1.0.20210614-java-16\kernel.jar --runtime-dir=C:\Users\stais\AppData\Roaming\jupyter\runtime --connection-file={connection_file}

Apparently the {connection_file} argument is not passed properly.

Steps to reproduce:

1. Download and install the Ganimede kernel as described here: github.com/allen-ball/ganymede which will add it to your current Jupyter installation.
   NOTE: the installation uses the "which" command, which does not exist on Windows. Copying "where.exe" to "which.exe" made it work.
2. Create a new notebook in VSCode and choose Ganymede as the kernel.
3. Write some code, e.g.: System.out.println("hello");
4. Run it ... you'll get the above error

[DonJayamanne]

Thanks for filing this issue, i can replicate this at my end, will look into getting this fixed.

[rchiodo]

@DonJayamanne is the PR done?

[DonJayamanne]

@taisbak
I believe I have fixed this issue. Please could you try the following to validate the fix:

• Install VS Code insiders
• Download the vsix from here & install it https://pvsc.blob.core.windows.net/extension-builds-jupyter-public/ms-toolsai-jupyter-insiders.kernelspec.argv.vsix
• If it doesn't work, please provide the logs again

Note: I"d like to get this validated before we merge this change into the main branch for the release.

[taisbak]

@DonJayamanne, thank you for the fast response.

• Installed the provided VSIX:
  

• Ganymede seems to get started OK.

• However, the Notebook hangs, when I try to run the code (I restarted everything, including my laptop):
  

• The output log does not provide anything useful:
  

• Other logs are empty.

• It is using a lot of CPU:
  

• Please let me know what other information you need.

[taisbak]

Maybe I've spotted the problem.
The -jar argument in Kernel.json has been changed from C:\users\me\Appdata... to ~\Appdata... which doesn't seem to work.
Kernel.json:
{
"argv": [
"java",
"--illegal-access=permit",
"--add-opens",
"java.base/jdk.internal.misc=ALL-UNNAMED",
"-jar",
"C:\\Users\\stais\\AppData\\Roaming\\jupyter\\kernels\\ganymede-1.1.0.20210614-java-16\\kernel.jar",
"--runtime-dir=C:\\Users\\stais\\AppData\\Roaming\\jupyter\\runtime",
"--connection-file={connection_file}"
],
"display_name": "Ganymede 1.1.0.20210614 (Java 16)",
"env": {},
"interrupt_mode": "message",
"language": "java"
}

[taisbak]

Further the slash in "java.base/jdk.internal.misc=ALL-UNNAMED" is changed to a back-slash: "java.base\jdk.internal.misc=ALL-UNNAMED" though it's not a filename.

[DonJayamanne]

Thanks for the feedback.
I'm a little confused.
Is the kernelspec above from the disc, if thats the case, then we don't modify it. I'm assuming what you're trying to say is that it was generated incorrectly by what ever tool generated it. is that right?

If not, please could you provide the logs from the Jupyter Output panel so i can see what's going on.
Thanks again for your help validating this fix.

[taisbak]

Sorry for the confusion.

This is the Jupyter Output:

Pasting the command into the terminal window produces the following output:

Changing the filepath from ~ to it's full name in the terminal window:

Changing the back-slash to slash in "--add-opens java.base\jdk.internal.misc=ALL-UNNAMED" in the terminal window gives

This led me to think that the arguments in the argv array from KernelSpec.json are being modified on their way. It should only be {connection_file} being changed to the relevant file name, which seems to be done correctly. The other arguments should be left unchanged.

But I don't know where it's happening. Just that the same KernelSpec.json works fine with Jupyter Lab.

[taisbak]

I have tried to look further into the problem.

It might be that the slashes are only changed to back-slash when displayed, though I would rather see the actual value.

Further it looks like the kernel actually gets started but doesn't communicate with the client.

Is there a way to capture output from the kernel itself?

When run as an anaconda jupyter notebook it writes the following output to the console:

[taisbak]

Sorry for my contemplations being messy.

Looking at it, it it is clear that your fix did fix the stated problem.

And led to the next.

I'll close this and file another issue about the communication problems.

Thank you and my apollogies.