WHY_EXPORT_DOESNT_WORK.md

Why export Doesn't Work with VS Code Debugging

The Problem

When you run:

export ADURL=https://example.com
export ADU=username
export ADP=password
python -m google.adk.server.app_server 8080

It works in the terminal because the shell passes environment variables to the Python process.

But when you debug in VS Code (press F5), VS Code runs Python in a separate process that:

• Doesn't inherit your terminal's environment variables
• Has its own isolated environment
• Only gets variables from:
  1. .env file (if configured)
  2. launch.json env section
  3. System-wide environment variables (not shell exports)

Visual Explanation

Terminal Session:
┌─────────────────────────┐
│ export ADURL=...        │ ← Sets variable in THIS shell
│ python -m app_server    │ ← Inherits from shell ✅
└─────────────────────────┘

VS Code Debugger:
┌─────────────────────────┐
│ Press F5                │
│                         │
│ VS Code → Python        │ ← Separate process
│ (No shell variables)    │ ← Doesn't see export ❌
└─────────────────────────┘

Solutions

Solution 1: Use .env File (Recommended) ✅

VS Code can automatically load .env file:

1. Create .env in project root
2. Add variables:

   ADURL=https://example.com
   ADU=username
   ADP=password
   

3. VS Code loads it automatically (via envFile in launch.json)

Why this works:

• VS Code reads .env file directly
• No need to export in terminal
• Works for both debugging AND terminal

Solution 2: Set in launch.json ✅

Add to .vscode/launch.json:

"env": {
  "ADURL": "https://example.com",
  "ADU": "username",
  "ADP": "password"
}

Why this works:

• VS Code passes these directly to the debug process
• Works for debugging

Solution 3: Set in Shell Profile (Partial) ⚠️

Add to ~/.zshrc or ~/.bashrc:

export ADURL=https://example.com
export ADU=username
export ADP=password

Why this partially works:

• ✅ Works for terminal: python -m app_server
• ❌ Doesn't work for VS Code debugging (unless you restart VS Code after setting)
• ⚠️ VS Code only reads system environment on startup

Solution 4: Use Terminal Profile in VS Code ⚠️

In .vscode/settings.json:

{
  "terminal.integrated.env.osx": {
    "ADURL": "https://example.com",
    "ADU": "username",
    "ADP": "password"
  }
}

Why this partially works:

• ✅ Works for VS Code terminal
• ❌ Doesn't work for debugging (debugger uses different process)

Comparison

Method	Terminal Run	VS Code Debug	Notes
export in terminal	✅ Yes	❌ No	Only in that shell session
.env file	✅ Yes*	✅ Yes	*If using python-dotenv
launch.json env	❌ No	✅ Yes	Only for debugging
Shell profile (~/.zshrc)	✅ Yes	⚠️ Maybe	Only if VS Code restarted

Why VS Code Debugger is Different

1. Separate Process: Debugger runs debugpy which spawns Python in a new process
2. Isolated Environment: Doesn't inherit from your terminal session
3. Security: Intentionally isolated to prevent environment pollution

Best Practice

Use .env file because:

• ✅ Works for both terminal and debugging
• ✅ Easy to manage
• ✅ Can be gitignored (keeps secrets safe)
• ✅ Standard practice

Quick Test

To verify what VS Code sees:

Add this to your code temporarily:

import os
print("ADURL:", os.getenv('ADURL', 'NOT SET'))
print("ADU:", os.getenv('ADU', 'NOT SET'))
print("ADP:", os.getenv('ADP', 'NOT SET'))

Run in:

1. Terminal: python -m google.adk.server.app_server 8080 → Should show values if exported
2. VS Code Debugger (F5): → Will show "NOT SET" unless you use .env or launch.json

Summary

export doesn't work with VS Code debugging because:

• VS Code debugger runs in a separate process
• It doesn't inherit your terminal's environment
• It only reads from .env file or launch.json env section

Solution: Use .env file - it works for both terminal and debugging!