Analysis of the Environment

VS Code for Web (vscode.dev / github.dev) runs entirely within the
browser's security sandbox. This creates a fundamental disconnect for
standard desktop extensions.

1. Why Python Extensions Fail

• Runtime Absence: The Python extension is a Node.js-based tool
  that expects a local Python interpreter (python.exe). Browsers
  cannot execute local binaries.
• API Constraints: Standard extensions use os, fs, and
  child_process modules. These APIs are unavailable in the browser.
• Requirement: Only extensions explicitly authored as
  "Web Extensions" (using a Worker-based architecture) will run.

2. Status of Debugging Extensions

• General Rule: Debugging usually requires a "Debug Adapter" to
  communicate with a running process. Since the browser cannot spawn
  processes, most debuggers (Python, C++, Java) are incompatible.
• Exception: You can debug client-side JavaScript/TypeScript code
  because that code is already running within the browser's engine.

3. Proposed Workarounds

To obtain full Python debugging in a browser, the user must provide a
remote "compute" backend:

• GitHub Codespaces: Provides a full VM container where the
  extension can run in a proper Node.js environment.
• Remote Tunnels: Allows the web UI to connect to a local
  machine's resources via an encrypted tunnel.

https://www.youtube.com/watch?v=2sdXMJZKLJE

This video (published Nov 2024) provides a direct tour of vscode.dev and confirms the points we discussed:

• Disabled Debugging: The video explicitly shows that the debugging icon is disabled in the web version [01:29].
• Extension Availability: It demonstrates how to identify incompatible extensions. If an extension is shaded out in the search results, it will not work on the web [06:25].
• Web-Compatible Extensions: It shows that "declarative" extensions—like the Night Owl theme or the VS Code Pets extension—work because they don't require a local backend [06:32].
• The Solution (Remote Tunnels): The video highlights Remote Tunnels as the primary way to get a terminal and full language support (like Python) while still using the browser interface [01:40].