[BUG] macOS arm64: 2.1.37 hangs on startup; install.sh hangs at setup

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported for this exact macOS startup behavior
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

On macOS arm64, Claude Code 2.1.37 hangs immediately on startup with no output.

• claude --version hangs forever (no stdout/stderr)
• claude --help hangs forever
• curl -fsSL https://claude.ai/install.sh | bash also hangs during setup because it downloads latest (2.1.37) and then blocks on:

/Users/<user>/.claude/downloads/claude-2.1.37-darwin-arm64 install

What Should Happen?

claude --version and claude --help should return immediately, and the installer should complete.

Error Messages/Logs

No CLI output at all (stdout/stderr are empty while process is stuck).

sample while hung shows the process stuck at loader start:

Analysis of sampling 2.1.37 ...
_dyld_start (in dyld)

Steps to Reproduce

1. macOS arm64
2. Install/use native Claude Code 2.1.37
3. Run:

claude --version

1. Observe: hangs forever, no output

Also reproducible via installer:

curl -fsSL https://claude.ai/install.sh | bash

Installer currently resolves:

latest=2.1.37

and then hangs at .../claude-2.1.37-darwin-arm64 install.

Regression?

Yes.

Last Working Version

2.1.36 and 2.1.34 both work on this machine.

Observed locally:

2.1.34 EXIT stdout='2.1.34 (Claude Code)'
2.1.36 EXIT stdout='2.1.36 (Claude Code)'
2.1.37 HANG stdout=0 stderr=0

Important Related Repro (Likely Separate Resume Bug)

Even on 2.1.36, --continue can freeze in one project directory while simple flags work:

# Works
~/.local/share/claude/versions/2.1.36 -v
# => 2.1.36 (Claude Code)

# Also works
~/.local/share/claude/versions/2.1.36 -v

# Freezes (0% CPU, no output)
~/.local/share/claude/versions/2.1.36 --dangerously-skip-permissions -c

Observed behavior:

• In ~, -c exits with No conversation found to continue.
• In this repo, -c hangs and debug logging stops at:
• [render] initLayout starting
• Layout engine: yoga
• If the most recent session file for this repo is temporarily moved aside, -c stops freezing and exits with No conversation found to continue.

Claude Code Version

2.1.37

Platform

Anthropic API

Operating System

macOS (arm64)

Terminal/Shell

zsh (Terminal)

Additional Information

Potentially related issues with install/startup hangs in other environments:

• #24258
• #23601
• #22047

---

Related Issue / Why Separate

Related: #24325

Filed separately because this report is about a startup/install blocker in 2.1.37:

• claude --version / --help hang with no output
• install.sh hangs when invoking the downloaded 2.1.37 binary

This appears to happen before normal CLI interaction, while #24325 focuses on a different 2.1.36 runtime/TUI freeze path after UI render (input unresponsive, resume-context-sensitive).