Environment variable not being passed down on VS Code in Windows -- bug or am I missing something?

Question

I am doing development with https://github.com/google/clasp. clasp will use the environment variable clasp_config_auth. I have tested and confirmed that outside of VS Code if I set the environment variable clasp_config_auth then clasp picks it up and works as expected.

But in VS Code it does not work as expected.

I have the following in my tasks.json:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "options": {
        "env": {
            "clasp_config_auth": "~/path/to/file/.clasprc.json.me"
        }
    },
    "windows": {
        "options": {
            "env": {
                "clasp_config_auth": "%userprofile%\\path\\to\\file\\.clasprc.json",
            }
        }
    },
    "tasks": [
        {
            "label": "push to GAS",
            "type": "shell",
            "command": "clasp push",
            "group": {
                "kind": "build",
                "isDefault": true
            },
        }
    ]
}

Now, if I try to run the push to GAS task, I get this error:

> Executing task: clasp push <

ENOENT: no such file or directory, open 'C:\Users\me\Documents\work\project\%userprofile%\path\to\file\.clasprc.json'
The terminal process "C:\windows\System32\cmd.exe /d /c clasp push" terminated with exit code: 1.

C:\Users\me\Documents\work\project\ is the current working directory of my project.

It looks like VS Code is not setting the environment variable properly so clasp picks up C:\Users\me\Documents\work\project\%userprofile%\path\to\file\.clasprc.json instead of %userprofile%\path\to\file\.clasprc.json or C:\Users\me\path\to\file\.clasprc.json.

If I set the environment variable in a Command prompt and run clasp push it works as expected. But in VS Code it does not.