When python.pythonPath includes ${workspaceFolder}, tasks that use ${config:python.pythonPath} fail to start

[brettcannon]

From @segevfiner on August 28, 2018 22:39

Environment data

• VS Code version: 1.26.1
• Extension version (available under the Extensions sidebar): 2018.7.1
• OS and version: Windows 10.0.17134.228 x64
• Python version (& distribution if applicable, e.g. Anaconda): CPython 3.7.0 x64
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): virtualenv

Actual behavior

When python.pythonPath includes ${workspaceFolder}, tasks that use ${config:python.pythonPath} fail to start:

> Executing task: ${workspaceFolder}\venv\Scripts\python.exe setup.py build_ext --inplace <

The system cannot find the path specified.
The terminal process terminated with exit code: 1

Terminal will be reused by tasks, press any key to close it.

Expected behavior

The tasks should start correctly. It's quite useful to use ${config:python.pythonPath} in your tasks so as to use the Python version used by vscode-python to run the tasks.

Steps to reproduce:

1. Create a virtualenv under your workspace: virtualenv venv
2. Select it as the Python interpreter of VS Code using the status bar. (python.pythonPath should be set to a path using ${workspaceFolder}).
3. Create a task that uses ${config:python.pythonPath} to run anything you want, and try to run it.

Logs

Nothing relevant under default log level.

Copied from original issue: microsoft/vscode-python#2459

[brettcannon]

From @bhrutledge on August 29, 2018 13:47

I stumbled upon this issue by way of #1664.

My workspace settings (set automatically, I think):

{
    "python.pythonPath": "${workspaceFolder}/venv/bin/python"
}

What I tried:

{
    "label": "runserver",
    "type": "shell",
    "command": "${config:python.pythonPath} manage.py runserver",
    "problemMatcher": [],
    "group": {
        "kind": "build",
        "isDefault": true
    }
}

Output:

> Executing task: ${workspaceFolder}/venv/bin/python manage.py runserver <

/usr/local/bin/bash: /venv/bin/python: No such file or directory
The terminal process terminated with exit code: 127

Changing command to ${workspaceFolder}/venv/bin/python manage.py runserver works. Just using manage.py runserver doesn't work because the virtualenv isn't activated. Of course, if I were using pipenv, I'm guessing pipenv run manage.py runserver would do the job.

Aside: this makes me wonder if VS Code has a facility for defining a new task type, that would handle the virtualenv automatically.

[dbaeumer]

This is actually not task related. What the user does is configuring a like this "python.pythonPath": "${workspaceFolder}/venv/bin/python" but to my knowledge settings can't contain variables.

WE can do two things:

@sandy081 allow variables in settings in the first place
@isidorn improve the configuration resolver so that it looks at the value of a setting and if a variable is in there replaces it as well

Opinions?

[isidorn]

@dbaeumer we do not support variables in settings - adding it would be a big door which I am not sure I would like to open.
Option 2 does not really make sense since we do not support variables in settings, so I am not sure why we should resolve again.

For now I suggest no action, and if more users ask for this we can look in Option 2 (which feels a bit ugly).

fyi @weinand