[BUG] Grep tool completely non-functional on Windows (native binary installation) - returns "No matches found" for all searches

Description:

The built-in Grep tool in Claude Code is not working at all on Windows. It returns "No
matches found" for every search query, even when the patterns clearly exist in the
files. Claude Code is working perfectly, /status and /doctor report no issues, and /ide integration with VS Code works perfectly.

Environment:

• OS: Windows 11 24H2 x64
• Claude Code version: v1.0.69
• Installation type: native binary installation (powershell)
• Working directory: D:\Projects\4numeri

Steps to Reproduce:

1. Create any file with known content (e.g., HTML file with "xlsx" text)
2. Use Claude Code's Grep tool to search for that content
3. Tool returns "No matches found" despite the text being present

Expected Behavior:
The Grep tool should find and return matching lines with line numbers.

Actual Behavior:
The Grep tool always returns "No matches found" regardless of:

• Search pattern (simple text or regex)
• File type (.html, .md, .txt)
• Path format (relative, absolute, Windows-style, Unix-style)
• Pattern content (with or without special characters)

Example:
File content contains: <script
src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.18.5/xlsx.full.min.js"></script>

Grep tool search: pattern="xlsx", path="4numeri.html"
Result: "No matches found"

System grep (working): grep -n "xlsx" "D:/Projects/4numeri/4numeri.html"
Result: Found 11 matches

Workaround:
Using the Bash tool with system grep works correctly: grep -n "pattern" "path"

Additional Notes:

• System GNU grep (version 3.0) works perfectly through the Bash tool
• The issue affects all search patterns, not just those with special characters
• This makes the internal Grep tool completely unusable on Windows