Claude Code 2.1.122 crashed with embedded Bun v1.3.14 segfault at address 0x38

Resolved 💬 3 comments Opened Apr 29, 2026 by Taeu Closed May 2, 2026

Summary

Claude Code crashed with an embedded Bun segfault while editing code in a long-running session.

This appears to be a native runtime crash in the Claude Code/Bun wrapper rather than application code: the terminal printed Bun's crash banner and provided a bun.report URL.

Crash details

  • Claude Code version in crashed session: 2.1.122
  • Current claude --version after restart: 2.1.123 (Claude Code)
  • Runtime shown in crash banner: Bun v1.3.14 (0a466a11) macOS Silicon
  • OS: macOS arm64
  • sw_vers: ProductVersion 26.2, BuildVersion 25C56
  • crash banner displayed: macOS v26.27
  • Invocation args in crash banner: "claude" "--dangerously-skip-permissions"
  • Claude Code session id: 7c4589b6-814b-409e-a686-167dc4bd1a2c
  • Bun crash report URL:
  • https://bun.report/1.3.14/M_10a466a1mgkgkEuhogC____________urxjpDmnnyxCmv+mIu+78fm/9tc+501M2l/2W+0+1WA2AwD

What was happening

Claude Code was in a long-running coding session, editing Python backend files. The immediate visible task before the crash was:

S4 — reject atomic transition + S5 approve rollback event 위치 수정

Right before that, Claude Code had successfully applied an edit for:

S3 — child terminal lifecycle (parent request_status 갱신)

Then the UI showed:

✽ Symbioting… (2m 10s · ↓ 10.0k tokens · thought for 14s)

After that, the process crashed with the Bun banner below.

Crash excerpt

Bun v1.3.14 (0a466a11) macOS Silicon
Args: "claude" "--dangerously-skip-permissions"
Elapsed: 10620675ms | User: 817964ms | Sys: 175876ms
RSS: 0.20GB | Peak: 0.46GB | Commit: 0.02ZB | Faults: 51252 | Machine: 8.59GB

panic(main thread): Segmentation fault at address 0x38
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Expected behavior

Claude Code should not crash the process. If an internal tool/model/runtime error occurs, it should surface as a recoverable CLI error and preserve the active session state.

Actual behavior

The Claude Code process terminated with a Bun segmentation fault. The terminal became unusable and had to be restarted/resumed manually.

Notes

  • I checked ~/Library/Logs/DiagnosticReports and did not find a matching .ips crash report.
  • The crash happened during agent/editor activity, not while running project tests or executing the edited application code.
  • The session was resumable afterward, but the crash interrupted an in-progress multi-step code edit.

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