launch.json environment variables not being passed to Python scripts

[duncanw]

Environment data

• VS Code version: 1.37.1
• Extension version (available under the Extensions sidebar): 2019.8.30787
• OS and version: Windows 10
• Python version (& distribution if applicable, e.g. Anaconda): 2.7.13
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): virtualenv
• Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info How to update the language server to the latest stable version #3977): Jedi Enabled = True

Expected behaviour

Environment variables configured in launch.json should always be set when a python script is run or debugged.

Actual behaviour

Environment variables configured in launch.json are sometimes set when a python script is run or debugged. Sometimes they are not.

Steps to reproduce:

In my launch.json I have:

"configurations": [
        {
            "name": "Python: current jobs",
            "type": "python",
            "request": "launch",
            "program": "${workspaceFolder}/beany/beany/util/reporting/weeklywip.py",
            "console": "integratedTerminal",
            "env" : {
                "SANDBOX" : 1
            }    
        }
]

When debugging this, sometimes the command line includes the SANDBOX environment variable:

PS D:\workspace\vscode> cd 'd:\workspace\vscode'; ${env:SANDBOX}='1'; ${env:PYTHONIOENCODING}='UTF-8'; ${env:PYTHONUNBUFFERED}='1'; & 'd:\workspace\vscode\beany\env\Scripts\python.exe' 'c:\Users\dunca\.vscode\extensions\ms-python.python-2019.8.29288\pythonFiles\ptvsd_launcher.py' '--default' '--client' '--host' 'localhost' '--port' '50043' 'D:\workspace\vscode/beany/beany/util/reporting/weeklywip.py'

...but sometimes it doesn't, and the environment variable isn't available to the script:

PS D:\workspace\vscode> & 'd:\workspace\vscode\beany\env\Scripts\python.exe' 'c:\Users\dunca\.vscode\extensions\ms-python.python-2019.8.29288\pythonFiles\ptvsd_launcher.py' '--default' '--client' '--host' 'localhost' '--port' '50035' 'D:\workspace\vscode/beany/beany/util/reporting/weeklywip.py'

If I edit and save weeklywip.py before running it seems more likely to include the environment variable as desired, but I haven't figured out a clear pattern. This only started happening since Visual Studio Code updated to version 1.37.0 on 2019-08-08.

[kimadeline]

Hi @duncanw 👋 thank you for reporting this issue!

I can confirm that I can reproduce it in the following cases:

• VS Code 1.37.1 - Python extension 2019.8.30787 - Python 2.7.10
• VS Code 1.37.1 - Python extension 2019.8.30787 - Python 3.7.3 (venv)
• VS Code 1.37.1 - Python extension 2019.6.24221 - Python 2.7.10
• VS Code 1.38.0 (Insiders) - Python extension 2019.8.30787 - Python 2.7.10
• VS Code 1.38.0 (Insiders) - Python extension 2019.8.30787 - Python 3.7.3 (venv)

A few interesting notes:

• This behaviour only happened for the first run in the Python Debug Console terminal, subsequent runs were as expected. If the terminal was closed, then the behaviour would reappear.
• Even though the environment variable was not added to the command being executed, it was still available to the script:

[food2Code]

Hi @kimadeline
I've encountered this behaviour in VSCode 1.41.1.
I can confirm your findings except one case.
If one defines environment variable with value set to int, it is not available to the script at the first run:

For code:

import os

print(os.environ['TEST'])

below configuration fails at first run, works for subsequent

{
      "name": "Python: Current File 1",
      "type": "python",
      "request": "launch",
      "program": "${file}",
      "console": "integratedTerminal",
      "env": {
        "TEST": 1,
      }
    },

but this configuration works for every run

{
       "name": "Python: Current File 2",
      "type": "python",
      "request": "launch",
      "program": "${file}",
      "console": "integratedTerminal",
      "env": {
        "TEST": "1",
      }
    },

[dehai]

Hi @kimadeline , the latest version still have this issue. detail info listed below:

• VS Code 1.44.2 - Python extension 2020.4.76186 (27 April 2020) - Python 3.8.1 (venv)
• OS and version: Windows 10

still can not set env variables from launch.json,
how could solve this? and when, thanks!

[kimadeline]

Hello @dehai,

We haven't addressed this bug yet, please upvote the original comment to bump up its priority.

According to the comment above yours it is possible to set environment variables in the launch.json like this:

{
       "name": "Python: Current File 2",
      "type": "python",
      "request": "launch",
      "program": "${file}",
      "console": "integratedTerminal",
      "env": {
        "TEST": "1",
      }
},

[dsielert]

This is a decent broken existing feature nearly a year later and still no fix ?