Python debugging Unhandled: on_readmemory_request not available in PyDevJsonCommandProcessor.

[LittleBen42]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version:
  Version: 1.100.1 (user setup)
  Commit: 91fa95bccb027ece6a968589bb1d662fa9c8e170
  Date: 2025-05-09T15:43:50.040Z
  Electron: 34.5.1
  ElectronBuildId: 11369351
  Chromium: 132.0.6834.210
  Node.js: 20.19.0
  V8: 13.2.152.41-electron.0
  OS: Windows_NT x64 10.0.22631

Steps to Reproduce:

I have an issue with debugging my Python application since few type.

I'm using Python Debugger and I have the following output on the debug console:

Unhandled: on_readmemory_request not available in PyDevJsonCommandProcessor.

The debugger hangs and there is no possibility to break the execution.

Only CTRL+C in the debug console is working to exit this debug sesssion

Line 987 is the first breakpoint in my application.

[eleanorjboyd]

hm very interesting it is coming from the bundled part of the debugger extension. Can you try uninstalled and reinstalling the python debugger repo? Also what version of python are you using?

[LittleBen42]

Hi @eleanorjboyd,

I don't see the issue anymore.
I was using Python 3.10.4 and I have updated to Python 3.13.3, I have updated my venv to the new Python 3.13.3 and re install all my dependencies packages.

I have mentioned that the issue was present with all extension disabled but I have forget to restart vscode, therefore I need at least the Python extension.

Best Regards,

Benjamin

[eleanorjboyd]

Thanks for the update! Feel free to re-open in the future if you see it again!

[LittleBen42]

Hi @eleanorjboyd ,

I have changed my PC this week and I'm facing the error again.
For my old project, I have regenerated the venv and everything is fine so far.

I have started a new project and created a venv with the python extension from vscode. I have install pandas package and I'm using a very simple code

import pandas
import sys

def main():
    print(sys.argv[1])
    excel = pandas.read_excel(sys.argv[1])
    print(excel)
    return



if __name__ == "__main__":
    main()

and when I start the debugger I have the error again

Unhandled: on_readmemory_request not available in PyDevJsonCommandProcessor.

the debugger is launched with the following commands :

x:; cd '<work_dir>'; & '<work_dir>\.venv\Scripts\python.exe' 'c:\Users\<me>\.vscode\extensions\ms-python.debugpy-2025.8.0-win32-x64\bundled\libs\debugpy\launcher' '56250' '--' '<work_dir>\perso_parser.py'

So far didn't manage to solve it.

I'm using Python 3.13.5 on this new setup and vscode 1.101.2 (user setup)

[eleanorjboyd]

Hi! Can you send over your launch.json you are running? The error suggests you are using the legacy debugger and not the recent debugpy.

[LittleBen42]

Hi @eleanorjboyd

here is my launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python Debugger: Current File with Arguments",
            "type": "debugpy",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal",
            "args": "${command:pickArgs}"
        },
        {
            "name": "Python Debugger: Current File",
            "type": "debugpy",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal"
        }
    ]
}

I'm using this python extension ms-python.debugpy-2025.8.0-win32-x64

Thanks,

Benjamin

[LittleBen42]

Hi @eleanorjboyd ,

I have regenerated the venv with the python extension and looks like there was a missing dependencies in the pandas package.
I'm now using the default Python Debugger (I no longer have a launch.json) and I don't have the issue anymore.

I have installed Python 3.13.5 which is now configuring the path with the Launch directory with py.exe instead of usual python.exe.
When I have the issue initially, I have change my PATH to point on the Python3.13 directory which hold the python.exe
WIth this setup, I have the issue.

I have reverted back to the standard config (with Launch directory) and I have regenerated the venv and now everything is working as previously.

Best Regards,

Benjamin