Claude Code terminal crashed mid change due while reading emoji.

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?

Claude was trying to update my implementation plan tracker with the completed phases and adding checkbox emoji. The thread crashed the whole CLI twice.

What Should Happen?

Claude should not crash.

Error Messages/Logs

thread '<unnamed>' (22429222) panicked at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb/library/core/src/str/mod.rs:833:21:       
byte index 2 is not a char boundary; it is inside '✅' (bytes 0..3) of `✅ `                                                        
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace                                                       
fatal runtime error: failed to initiate panic, error 5, aborting                                                                    
zsh: abort      claude

Steps to Reproduce

Not entirely sure- has not happened before.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.3 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_