claude-code - 💡(How to fix) Fix Bun segfault on image attachment crashes session (Claude Code 2.1.142, Windows)

Summary

Attaching an image to a message reliably crashes the local session on Windows. The Bun runtime panics with a segmentation fault. No image attachment ever succeeds; the same operation reportedly works on other machines.

Environment

• Claude Code: 2.1.142
• Desktop app: Claude 1.8089.1.0 (Microsoft Store install)
• Runtime: Bun v1.3.14 (d2989145) Windows x64 (baseline)
• OS: Windows 10 Pro 10.0.19045
• CPU features: sse42, avx, avx2
• Machine RAM: 16.79 GB

Steps to reproduce

1. Start a local session in Claude Code 2.1.142.
2. Attach an image to the next user message (text content can be empty).
3. Send.

Expected

Image is processed and included in the message.

Actual

The Claude Code CLI process (claude.exe, Bun-based) crashes with a segfault immediately after sendMessage is invoked with imageCount=1. The session enters an unhealthy cycle (reason=no_response) and the message never reaches the model. Reproduces 3+ times back-to-back in the log.

Log excerpt (%APPDATA%\Claude\logs\main.log)

LocalSessions.sendMessage: ... messageLength=0, imageCount=1, toolStates=0
panic(main thread): Segmentation fault at address 0x0
oh no: Bun has crashed. This indicates a bug in Bun, not your code.
https://bun.report/1.3.14/e_1d298914mgkgkEuhogCCcKERNELBASE.dll6tmgBCSastMC.dllk6nMCSastMC.dllqt3UCSastMC.dll4i5U0wm40B__kkkm2CA2AA
[CCD CycleHealth] unhealthy cycle for local_<id> (Xs, hadFirstResponse=false, reason=no_response)

Crash modules in trace: KERNELBASE.dll, MC.dll (Windows locale / message-compiler boundary).

Notes

• Started after a recent auto-update to 2.1.142. Prior versions handled image attachment correctly on the same machine.
• Working directory contained a non-ASCII path, but the issue also reproduces from ASCII-only working directories (per user), so the path is unlikely to be the trigger.
• The bundled Bun is 1.3.14 baseline — pinning a newer or "modern" Bun build may be worth testing on the maintainer side.