[BUG] Claude Code Homebrew cask hangs on startup on macOS 26.3 (arm64)

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?

Environment:

• claude-code 2.1.49 (Homebrew cask)
• macOS 26.3 (25D125)
• Apple Silicon (arm64)

Description:
Claude Code hangs on startup — all commands including claude --version hang indefinitely. The binary never reaches main().

Debugging performed:

• Reinstalling via brew reinstall claude-code doesn't help
• Removing ~/.claude doesn't help
• Removing quarantine xattrs doesn't help
• lsof shows no open files/sockets beyond stdin/stdout/stderr
• sample shows the process stuck in _dyld_start (dyld) — the dynamic linker never finishes

Sample output:
Call graph:
7808 Thread_82181: Main Thread
7808 _dyld_start (in dyld) + 0 [0x10ddfc9c0]

Linked libraries (all system):
/usr/lib/libicucore.A.dylib
/usr/lib/libresolv.9.dylib
/usr/lib/libc++.1.dylib
/usr/lib/libSystem.B.dylib

Workaround:
Installing via npm (npm install -g @anthropic-ai/claude-code) works.

What Should Happen?

Claude Code should not hang on startup

Error Messages/Logs

Steps to Reproduce

1. Install claude-code via Homebrew on MacOS 26.3: brew install --cask claude-code
2. Run any command: claude --version
3. The process hangs indefinitely — no output, no crash, requires manual kill

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.49

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_