[BUG] Claude Code crashes with Bun panic in Visual Studio Code on Windows 11

[DenisKrav]

Preflight Checklist

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

What's Wrong?

Environment
OS: Windows 11
VS Code Extension: Claude Code v2.1.11
Bundled Bun version: v1.3.5 (1e86cebd)
CPU: x64 (baseline) with sse42, avx, avx2

Problem
Claude's code constantly crashes when opening a certain project, but even on projects that work, the error appears. The extension works fine on other projects. The crash occurs during initialization with a Bun panic error.

Observations

1. The --model "d" argument appears truncated/corrupted (should be full model name or "default")
2. Memory usage is very high (3.54GB RSS) before crash
3. Crash happens consistently on this project but not on others
4. Crash report URL: https://bun.report/1.3.5/e_11e86cebGugogCw+kiM65ioJgqpmMCYKERNEL32.DLLut0LCSntdll.dll4zijBA0eNoFwcENACAMAsBVWM1ENHyosXzc3js53LyYxYYrWApkTHbkEZWRd/gBNAAPKQ

What I tried (none of these helped)

1. Installed global Bun v1.3.6 (extension still uses bundled v1.3.5)
2. Deleted .claude folder in project directory
3. Deleted tmpclaude-* temporary folders
4. Reinstalled the extension
5. Restarted VS Code

What Should Happen?

Expected behavior
Claude Code should start normally without crashing.

Additional context
The project is a medium-sized backend application with multiple subfolders. Other projects open without issues on the same machine with the same extension version.

Error Messages/Logs

Args: "c:\Users\ACER\.vscode\extensions\anthropic.claude-code-2.1.11-win32-x64\resources\native-binary\claude.exe" "--output-format" "stream-json" "--verbose" "--input-format" "stream-json" "--max-thinking-tokens" "0" "--model" "d"...

Elapsed: 4531ms | User: 2250ms | Sys: 2265ms
RSS: 3.54GB | Peak: 3.54GB | Commit: 3.56GB | Faults: 873251 | Machine: 34.19GB

panic(thread 18532): integer does not fit in destination type
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Steps to Reproduce

1. Install Claude Code extension v2.1.11 on VS Code (Windows 11)
2. Open a project with multiple subfolders and files (in my case: c:\Project_programing\Work\Yieldy\nytroseo\back)
3. Open Claude Code panel in VS Code
4. Extension attempts to initialize and index the project
5. Bun crashes with panic error before Claude Code becomes usable

Claude Model

None

Is this a regression?

I don't know

Last Working Version

No response

Claude Code Version

2.1.11

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

No response

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] VS Code extension crashes on Windows 11 (16GB RAM) with Bun panic: "integer does not fit in destination type" #19439
2. [BUG] Claude Code VScode completely broken on Windows - Bun 1.3.5 crashAll products crash on startup: #19453
3. [BUG] Bun v1.3.5 crashes on Windows with "integer does not fit in destination type" - prevents installation and startup #18567

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[Zamaroht]

I started getting this too, I can't use claude code

panic(thread 1441708): integer does not fit in destination type
oh no: Bun has crashed. This indicates a bug in Bun, not your code.