Trace trap (SIGTRAP / EXC_BREAKPOINT) on startup — Claude Code 2.1.1 on macOS 26.3 (arm64)

Preflight Checklist

• [x] I have searched existing issues
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Running claude exits immediately with zsh: trace trap claude. This happens even after disabling all plugins. claude --version and claude --help work; only interactive startup crashes.

Steps to Reproduce

1. macOS 26.3 (arm64), zsh in Ghostty
2. claude
3. Immediate SIGTRAP/trace trap crash

Expected Behavior

Claude Code launches the interactive session.

Actual Behavior

Immediate crash: zsh: trace trap claude

Environment

• Claude Code version: 2.1.1 (native build)
• OS: macOS 26.3 (25D5087f)
• Hardware: Apple Silicon (arm64), model Mac15,6
• Terminal: Ghostty (zsh)
• Plugins: all disabled (all enabledPlugins set to false in ~/.claude/settings.json)

Crash Report Summary

Crash report (local): ~/Library/Logs/DiagnosticReports/2.1.1-2026-01-08-190814.ips

• Exception: EXC_BREAKPOINT / SIGTRAP
• Triggered thread: Bun Pool 3
• ESR: (Breakpoint) pointer authentication trap IB

Logs

• Debug log (local): ~/.claude/debug/ac380475-6f09-47bf-91f1-5a4d7451c7dd.txt

Happy to provide full crash log / debug log on request.