Modifications in the `.env` are not immediately applied

Environment data

• VS Code version: 1.33.1
• Extension version (available under the Extensions sidebar): 2019.4.1 (python extension)
• OS and version: Linux x64 4.15.0-48-generic snap
• Python version (& distribution if applicable, e.g. Anaconda): 3.6
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): conda

Expected behaviour

Changes in the .env file, its filename, the python.envFile setting or the envFile setting are immediately taken into account

Actual behaviour

Conditions: Unit tests with pytest

For example, in order for the setting python.envFile to be taken into account (if added or updated), I had to relaunch VSCode or close the folder and reopening it. The same situation occurs when I motidy my .env file.

sidenote: it is not clear whether to use envFile or python.envFile…

settings.json

{
    "python.linting.pylintEnabled": false,
    "python.linting.pep8Enabled": true,
    "python.linting.enabled": true,
    "python.linting.pep8Args": ["--max-line-length=120" ],
    "python.pythonPath": "/home/<user>/miniconda2/envs/dspt/bin/python",
    "python.testing.unittestEnabled": false,
    "python.testing.pyTestEnabled": true,
    "python.testing.nosetestsEnabled": false,
    "python.testing.autoTestDiscoverOnSaveEnabled": true,
    "python.envFile": "${workspaceFolder}/.env"
}

launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Current File (Integrated Terminal)",
            "type": "python",
            "request": "test",
            "program": "${file}",
            "console": "integratedTerminal"
        }
   ]
}

.env file

TEST_VAR="foo"

Test case

import os
import pytest


def test_env():
    a = os.environ.get("TEST_VAR")
    assert a == 'foo'
```

Normally everything should be great and the test is PASS
Now, 
* change the `TEST_VAR` to `bar` and the test is also be PASS
* another example, rename `.env` file to `test.env` and withou modifying the `settings.json` file, and the test is still be PASS

[example.zip](https://github.com/Microsoft/vscode-python/files/3132884/example.zip)

[dfinninger]

@gandroz Thanks for the hint about restarting VS Code to get this working. I have been beating my head against this for a little while and it’s good to have a workaround.

Maybe I can add another wrinkle to this story: when I run pytest in debug mode, it picks up the .env changes immediately. When running the tests normally (no debug) I needed to restart VS Code. I’m doing all of this through the test explorer with default launch.json configs.

workspace settings.json:

{
    "python.pythonPath": "<private>/.pyenv/versions/<private>/bin/python",
    "python.unitTest.pyTestArgs": [
        "src/python/"
    ],
    "python.envFile": "${workspaceFolder}/.env",
    "python.unitTest.unittestEnabled": false,
    "python.unitTest.nosetestsEnabled": false,
    "python.unitTest.pyTestEnabled": true
}

[luabud]

I believe this is actually a dupe of https://github.com/microsoft/vscode-python/issues/3805.