[BUG] Bun Bus error crash on macOS Silicon when pasting image (chat:imagePaste)

Additional info from reporter

• Drag-and-drop image paste works fine — no crash
• The crash is only triggered by the keyboard shortcut (Cmd+V → chat:imagePaste action)
• This suggests the bug is in the clipboard-reading code path specifically, not in image processing itself

The keybinding in question (from keybindings.json line 29):

"cmd+v": "chat:imagePaste"

Full stack trace from Bun crash report

The reporter also submitted the crash via bun.report. Stack trace confirms the crash is in a NAPI native binding during clipboard read:

Bus error at address 0x0BAD4007

- 8 unknown/js code
- NapiClass.cpp:68: long long Zig::NapiClass_ConstructorFunction<false>
- 1 unknown/js code
- jsc_llint_commonCallOp (LowLevelInterpreter64.asm)
- llint_call_javascript
- JSMicrotask.cpp:132: JSC::runInternalMicrotask
- VM.cpp:1437: JSC::VM::drainMicrotasks
- BunProcess.cpp:3511: Bun::jsFunctionDrainMicrotaskQueue
- 2 unknown/js code
- llint_call_javascript
- Interpreter.cpp:1320: JSC::Interpreter::executeCallImpl
- CallData.cpp:70: JSC::call

Root cause appears to be: A NAPI class constructor (NapiClass_ConstructorFunction) is called with a bad pointer (0xBAD4007 — a sentinel/poison value), suggesting the native clipboard module returns or accesses freed/invalid memory when reading image data from the macOS clipboard via Cmd+V.

Note: This is in the bundled Bun standalone executable — updating system Bun has no effect. The fix needs to come from either:

1. Claude Code updating its bundled Bun version
2. Fixing the native clipboard integration code
3. An upstream Bun fix for NAPI class construction with clipboard data

It's what they get for using Bun/zig.

Root cause identified: Bun 1.3.11 NAPI crash — fixed in 1.3.12 canary

Summary

The crash is a Bun 1.3.11 bug in NAPI error handling, not a Claude Code bug. When new ImageProcessor() throws an error, Bun 1.3.11 dereferences a poison pointer (0xBAD4007) and panics instead of propagating the JS exception. Bun 1.3.12 canary already fixes this — the same code returns a normal error with no crash.

The regression was exposed by v2.1.83 (March 25), which changed native module loading from eager (at startup) to lazy (on first use). This moved the ImageProcessor construction from startup — where errors were handled — to the Ctrl+V code path, where the Bun panic kills the process.

Reproduction (standalone, no Claude Code needed)

1. Extract image-processor.node from the Claude standalone binary (it's an embedded Mach-O dylib in the __BUN segment at offset 0xb8111eb, 1652KB, links against AppKit/CoreGraphics/ImageIO)

1. Run with Bun 1.3.11:

const m = require("/path/to/image-processor.node");
new m.ImageProcessor(); // → Bus error at 0xBAD4007, process killed

1. Run the exact same code with Bun 1.3.12 canary:

const m = require("/path/to/image-processor.node");
new m.ImageProcessor(); // → Error: "Failed to create reference from Buffer" (graceful)

1. Run with Node.js 22:

const m = require("/path/to/image-processor.node");
new m.ImageProcessor(); // → Error: "Failed to create reference from Buffer" (graceful)

Fix

Claude Code needs to update its bundled Bun from 1.3.11 to 1.3.12+. The NAPI crash fix is already in the 1.3.12 canary. Once the error is thrown as a JS exception instead of a Bus error, Claude's existing fallback code path should handle it and image paste should work normally.

Environment

• macOS 26.4 (Tahoe), Apple M4 Pro — macOS 26 has been installed since August 2025, image paste worked fine until v2.1.83
• SIP disabled (verified not the cause — the standalone reproduction crashes regardless)
• Crash confirmed on v2.1.87, v2.1.91, v2.1.92, and v2.1.96 — all bundle Bun 1.3.11

Timeline

| Date | Event |
|------|-------|
| Mar 25 | v2.1.83 released — native module loading changed from eager to lazy |
| ~Mar 25-29 | Image paste crash begins |
| Mar 29 | v2.1.87 — version in original bug report |
| Apr 8 | Confirmed still crashes on v2.1.96; root cause identified and fix verified on Bun 1.3.12 canary |

Fixed in https://github.com/anthropics/claude-code/releases/tag/v2.1.97

Probably with:

• Improved image handling: pasted and attached images are now compressed to the same token budget as images read via the Read tool

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