Parent process venv is not passed through to python subprocesses when using internalConsole

[edwardpeek-crown-public]

Configuring "console": "internalConsole" for a launch target causes Python subprocesses spawned by the main debug process to not have their venv inherited correctly.

Repro. steps:

1. Create a venv and install cowsay
2. Open VS Code in the venv parent dir
3. Create files as follows:

test.py:

import subprocess
stdout = subprocess.check_output(["python", "-m", "cowsay", "-t", "test"])
print(stdout.decode())

.vscode/launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python Debugger: test.py",
            "type": "debugpy",
            "request": "launch",
            "program": "test.py",
            "console": "internalConsole", // Doesn't work
//            "console": "integratedTerminal", // Works
        }
    ]
}

4. Launch the debug target

Actual outcome

• Dialog box with "Server disconnected unexpectedly" displayed
• "No module named cowsay" printed in debug console

Expected outcome

• Subprocess runs without error

Notes

The underlying cause seems to be that the PATH and VIRTUAL_ENV env vars are not inherited correctly in spawned subprocesses when they are intercepted for debugging.

[karthiknadig]

Internal Console vs Integrated Terminal is handled in the debug server, so moving this to debugpy.

I also noticed that you are using "python" instead of sys.executable. If I remember correctly that results in a shell execution, so it might not run with the same environment variables.

import subprocess
import sys
stdout = subprocess.check_output([sys.executable, "-m", "cowsay", "-t", "test"])
print(stdout.decode())