VS Code Codex extension on Windows adds ~19s delay to trivial commands

Environment

• Platform: Windows
• IDE: VS Code
• Codex usage: VS Code Codex extension only; standalone CLI not installed
• Workspace tested: normal repository and completely empty folder

Issue

The Codex extension was previously working normally, but now trivial shell commands take around 19 seconds or more inside Codex even though the same commands execute almost instantly in PowerShell.

Example observed in Codex:

Running command for 19s

The underlying command was only:

echo hello

Timing outside Codex

Measured directly in PowerShell:

Measure-Command { cmd /c echo hello }
TotalMilliseconds: 12.1011

Measure-Command { git status }
TotalMilliseconds: 50.5386

This shows that PowerShell, Git, disk access, and the repository itself are fast. The delay is introduced by Codex before or after actual process execution.

Isolation already performed

• Reinstalled and uninstalled/reinstalled the Codex extension
• Restarted/reloaded VS Code
• Tested in the main repository
• Tested in a completely empty folder
• Confirmed PowerShell and Git are fast outside Codex
• No standalone Codex CLI is installed
• The slowdown persists even for echo hello

Expected behavior

A trivial shell command should start and return in well under one second when the underlying command itself completes in milliseconds.

Actual behavior

Codex adds roughly 19 seconds or more of overhead to each simple command, making normal coding work impractical.

Possible relation

This appears closely related to the currently open Windows sandbox performance reports such as #32314, where the elevated native Windows sandbox adds 20–35 seconds before trivial commands even though the actual command execution is fast.

Please investigate the Windows sandbox/runner startup path used by the VS Code extension. A diagnostic in the extension showing sandbox setup time, ACL setup time, process launch time, and result propagation time would also make this much easier to troubleshoot.