[BUG] VS Code terminal output garbled with stray Unicode diacritical characters — resolves after reloading VS Code

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Every command run in the VS Code integrated terminal via Claude Code produces garbled output. Text characters are replaced with stray Unicode diacritical marks and unreadable symbols instead of normal ASCII/Latin output.

The corrupted output affects all commands run through Claude Code in the terminal. Notably, after exiting and reloading VS Code several times, the issue resolves itself — and even the previously garbled output in the terminal history appears normal again, suggesting a rendering/state issue rather than data corruption.

What Should Happen?

All commands run via Claude Code in the VS Code terminal should display clean, correctly-rendered ASCII/Latin text output at all times — without any Unicode diacritical corruption or garbled symbols.

Error Messages/Logs

Steps to Reproduce

1. Open VS Code with the Claude Code extension active.
2. 2. Open a project in VS Code.
3. 3. Ask Claude Code to run any shell command in the integrated terminal (e.g., git status, ls, npm install).
4. 4. Observe the terminal output — text appears garbled with stray Unicode diacritical characters and unreadable symbols instead of normal output.
5. 5. Exit VS Code completely and reopen it.
6. 6. Repeat steps 2–4 and observe the same garbled output.
7. 7. After exiting and reloading VS Code several more times, the output eventually appears normal — and previously garbled history also looks correct.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

v2.1.158

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

<img width="1568" height="548" alt="Image" src="https://github.com/user-attachments/assets/28c5b7b6-8f24-4d4e-b482-ee6af0ac4d66" />

Key observation: The garbled output is transient/ephemeral — after reloading VS Code several times the issue self-resolves, and even previously garbled history appears normal. This strongly suggests a terminal rendering/state issue rather than actual data corruption.

Related issues:

• #63138 [Bug] VSCode terminal output displays corrupted text with garbled symbols (open, 2 days ago)
• - #59660 Session-summary text renders garbled (box-drawing/Cyrillic glyphs) in Cursor terminal (open)

A screenshot showing the garbled output with stray Unicode diacritical characters is attached (see image provided with this report).