Python extension does not detect Python installations and throws an error

[kwmlodozeniec]

Environment data

• VS Code version: 1.56.2
• Extension version (available under the Extensions sidebar): XXX
• OS and version: v2021.5.842923320
• Python version (& distribution if applicable, e.g. Anaconda): 3.9.5, standard installation
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): venv and global installation
• Value of the python.languageServer setting: Pylance
• OS: Windows 10 1809 Build 17763.1935

Expected behaviour

The extension should correctly detect the installed python version without errors.

Actual behaviour

Extension fails to detect Python and throws an error in the output.

Steps to reproduce:

1. Install python extension, open a python file.

Logs

Python extension output

Error 2021-06-04 16:23:57: Failed to get interpreter information for 'C:\Program Files\Python39\python.exe' [Error: Command failed: "C:\\Program Files\Python39\python.exe" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\pyvsc-run-isolated.py" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\interpreterInfo.py"
�[91mParserError: 
�[96mLine |
�[96m   1 | �[0m … python.exe" �[96m"c:\Users\mlodozk\.vscode\extensions\ms-python.python-202�[0m …
�[96m     | �[91m               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[91m�[96m     | �[91mUnexpected token
�[96m     | �[91m'"c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\pyvsc-run-isolated.py"' in expression or statement.
�[0m

	at ChildProcess.exithandler (child_process.js:317:12)
	at ChildProcess.emit (events.js:315:20)
	at maybeClose (internal/child_process.js:1048:16)
	at Process.ChildProcess._handle.onexit (internal/child_process.js:288:5)] {
  killed: false,
  code: 1,
  signal: null,
  cmd: '"C:\\\\Program Files\\Python39\\python.exe" "c:\\Users\\mlodozk\\.vscode\\extensions\\ms-python.python-2021.5.842923320\\pythonFiles\\pyvsc-run-isolated.py" "c:\\Users\\mlodozk\\.vscode\\extensions\\ms-python.python-2021.5.842923320\\pythonFiles\\interpreterInfo.py"'
}

[karthiknadig]

Can you run this and share what you get?

"C:\Program Files\Python39\python.exe" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\pyvsc-run-isolated.py" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\interpreterInfo.py"

[kwmlodozeniec]

"C:\Program Files\Python39\python.exe" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\pyvsc-run-isolated.py" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\interpreterInfo.py"
ParserError:  
Line |
   1 |  … python.exe" "c:\Users\mlodozk\.vscode\extensions\ms-python.python-202 …
     |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Unexpected token '"c:\Users\mlodozk\.vscode\extensions\ms-python.python-2021.5.842923320\pythonFiles\pyvsc-run-isolated.py"' in 
     | expression or statement.

Okay, I have run the above in powershell and this is where I get the issue. The standard cmd gives me this:

{"versionInfo": [3, 9, 5, "final", 0], "sysPrefix": "C:\\Program Files\\Python39", "sysVersion": "3.9.5 (tags/v3.9.5:0a7dcbd, May  3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)]", "is64Bit": true}

But this was working absolutely fine until now.

[kwmlodozeniec]

Is there anything else I could try to help debug the issue?

[karrtikr]

We'll need to fix the error with powershell, it could be it's not able to parse certain unicode characters. What's the version of powershell you were using?

Did it ever used to work with the extension?
Can you try installing an older version of the extension (for example 2020.4.58038), and see if your problem happens?

You can follow the prompts from "Extensions: Install Specific Version of Extension..." in the command palette:

Or you can open the extensions side bar, click on the settings for the Python extension and pick "Install Another Version...":

[kwmlodozeniec]

My powershell version is 7.1.3
It used to work fine until a few weeks ago. I have tried a bunch of older version of the python extension without success, it's till reporting Python is not installed and not showing anything in the interpreter version in the status bar even when I select a new virtual env or point it to the system python installation.

[kwmlodozeniec]

I even tried changing the default shell to cmd and VS Code is still trying to load the PS script activation file. Could that be a clue? I have changed the default shell to PS a few weeks ago, but I seem to remember it was working.

Microsoft Windows [Version 10.0.17763.1935]
(c) 2018 Microsoft Corporation. All rights reserved.

C:\Users\mlodozk\AppData\Roaming\Code\User>& c:/repos/automated-regression-testing/pysystemtests/.env/Scripts/Activate.ps1
& was unexpected at this time.

C:\Users\mlodozk\AppData\Roaming\Code\User>

[karrtikr]

Oh I see, VSCode recently had a issue #16175 where the API was unable to detect the correct shell. Can you try VSCode insiders as mentioned here #16175 (comment) and see if it helps?

Either way, it seems the issue is either with powershell or VSCode, but not the extension itself as rolling back doesn't work.