[BUG] VS Code extension crashes on Windows 11 (16GB RAM) with Bun panic: "integer does not fit in destination type"

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?

The Claude Code VS Code extension consistently crashes during startup on Windows 11 machines with 16GB RAM. The crash is a Bun runtime panic with "integer does not fit in destination type" error. Memory usage reaches 2.75-3.28GB before crashing.

The CLI works perfectly on the same machine - only the VS Code extension crashes.

What Should Happen?

The extension should start normally without crashing.

Error Messages/Logs

Bun v1.3.5 (1e86cebd) Windows x64 (baseline)
Windows v.win11_ge
CPU: sse42 avx avx2
Args: "claude.exe" "--output-format" "stream-json" "--verbose" "--input-format" "stream-json" "--max-thinking-tokens" "31999" ...

Elapsed: 19672ms | User: 3953ms | Sys: 8203ms
RSS: 2.75GB | Peak: 2.77GB | Commit: 3.29GB | Faults: 1009877 | Machine: 16.86GB

panic(thread 11220): integer does not fit in destination type
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

https://bun.report/1.3.5/e_11e86cebGugogCw+kiM65ioJgqpmMCYKERNEL32.DLL65yECSntdll.dllw33WA0eNoFwcENACAMAsBVWM1ENHyosXzc3js53LyYxYYrWApkTHbkEZWRd/gBNAAPKQ


Additional errors in logs:
- `[ERROR] MCP server "claude-vscode" Failed to fetch tools: MCP error -32601: Method not found`
- `Ripgrep first use test: FAILED`

Steps to Reproduce

1. Install Claude Code extension v2.1.11 on Windows 11 with 16GB RAM
2. Open any project in VS Code
3. Extension attempts to start and crashes within 5-20 seconds

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

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

Environment:

• OS: Windows 11
• RAM: 16GB (7-8GB free at crash time)
• Bun Version: 1.3.5 (bundled with extension)
• Also tested in: Windsurf (VS Code fork) - same crash

Key observations:

• Memory usage is abnormally high (2.75-3.28GB RSS at startup)
• Works on 128GB workstation with identical setup
• CLI works perfectly on the same 16GB machine
• Crash occurs even with all MCP servers disabled

Troubleshooting performed:

| Test | Result |
|------|--------|
| Disabled MCP servers globally | Still crashes |
| Disabled MCP at project level | Still crashes |
| Removed .mcp.json file entirely | Still crashes |
| Installed MCP globally (avoid npx overhead) | Still crashes |
| Restarted computer | Still crashes |
| Tested in regular VS Code (not just Windsurf) | Still crashes |

Workaround: Using Claude Code CLI instead of the VS Code extension works correctly.