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Claude Code Issues / #25676

[BUG] panic(main thread): Segmentation fault at address 0x4469BAB7D20

Status Closed — not planned
Reported on v2.1.42
Maintainer reply None cached
Activity 12 comments · opened Feb 14, 2026 · closed Mar 26, 2026

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?

Bun Canary v1.3.9-canary.62 (6d2fefba) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "claude" "--dangerously-skip-permissions" "--resume"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) abort_signal(3538) fetch(46298) jsc spawn(11901) standalone_executable process_dlopen(3) yaml_parse(356)
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node:http2"
Elapsed: 55063493ms | User: 4489671ms | Sys: 834218ms
RSS: 0.77GB | Peak: 1.99GB | Commit: 5.25GB | Faults: 30798010 | Machine: 16.89GB

panic(main thread): Segmentation fault at address 0x4469BAB7D20
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

https://bun.report/1.3.9/e_26d2fefbmgkgEuhogCsppmqCyiu4RglgkvB0to7uB___A2skChuhyqkD

<img width="1658" height="502" alt="Image" src="https://github.com/user-attachments/assets/94dc03a4-a9f3-41ac-ab60-f5a742c05d40" />

<img width="434" height="33" alt="Image" src="https://github.com/user-attachments/assets/1ca883ed-87bb-418a-85a8-82e9f7f83485" />

What Should Happen?

no crash

Error Messages/Logs

Steps to Reproduce

I just used Claude Code to solve some issues. When Claude is running, it shows a segmentation fault, so I repport this segmentation fault issue.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.42 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_

View original on GitHub ↗

12 Comments

github-actions[bot] · 6 months ago

Found 3 possible duplicate issues:

  1. https://github.com/anthropics/claude-code/issues/25630
  2. https://github.com/anthropics/claude-code/issues/21875
  3. https://github.com/anthropics/claude-code/issues/24101

This issue will be automatically closed as a duplicate in 3 days.

  • If your issue is a duplicate, please close it and 👍 the existing issue instead
  • To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

mosjin · 6 months ago

Not same issue...
I used claude in cmd.exe, NOT nodejs claude. Also it's Bun v1.3.9. Also I run claude about 8 hours ago.
I wonder when this issue has fixed please? It's not friendly to end user...

MartinWickman · 6 months ago

This happens in 2.1.44. Windows 11, both in WSL and native. It happens regularly and seemingly random. At least once per hour. Show stopper for Windows users. This is with the powershell installation (native).

It's not related to context window usage. I get this crash randomly when the model is processing. 

============================================================
Bun Canary v1.3.9-canary.62 (6d2fefba) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "C:\Users\marti\.local\bin\claude.exe" "--continue"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(53) jsc spawn(115) standalone_executable process_dlopen yaml_parse(24)
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node:http2"
Elapsed: 96498ms | User: 13359ms | Sys: 2750ms
RSS: 0.97GB | Peak: 1.24GB | Commit: 1.27GB | Faults: 1054223 | Machine: 0.14TB

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

Bun v1.3.9 ([6d2fefb](<https://github.com/oven-sh/bun/tree/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8>)) on windows x86_64_baseline [_]

Segmentation fault at address 0xFFFFFFFFFFFFFFFF

  • [Allocator.zig:141](<https://github.com/oven-sh/zig/blob/bun-6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/lib/std/mem/Allocator.zig#L141>): rawRemap
  • [array_list.zig:422](<https://github.com/oven-sh/zig/blob/bun-6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/lib/std/array_list.zig#L422>): clearRetainingCapacity
  • [pipe.c:2211](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/win/pipe.c#L2211>): uv__process_pipe_write_req
  • [core.c:579](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/win/core.c#L579>): uv__process_reqs
  • [core.c:736](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/win/core.c#L736>): uv_run
  • [VirtualMachine.zig:340](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/bun.js/VirtualMachine.zig#L340>): onAfterEventLoop
  • [bun.js.zig:452](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/bun.js.zig#L452>): start
  • [bindings.cpp:4686](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/bun.js/bindings/bindings.cpp#L4686>): JSC__VM__holdAPILock
  • [VM.zig:35](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/bun.js/bindings/VM.zig#L35>): holdAPILock
  • [cli.zig:20](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/cli.zig#L20>): start
  • [main.zig:62](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/main.zig#L62>): main
  • [exe_common.inl:78](<https://github.com/oven-sh/bun/blob/6d2fefba4c4ff73f6cb1d6141ed44091b788b2c8/src/src/startup/exe_common.inl#L78>): invoke_main

Another one:

============================================================
Bun Canary v1.3.10-canary.63 (1979c945) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "claude" "--continue"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) abort_signal(2) fetch(73) jsc spawn(181) standalone_executable process_dlopen yaml_parse(33)
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node:http2"
Elapsed: 716610ms | User: 24625ms | Sys: 6218ms
RSS: 1.20GB | Peak: 1.82GB | Commit: 1.47GB | Faults: 1472136 | Machine: 0.14TB

panic(main thread): Segmentation fault at address 0xFFFFFFFFFFFFFFFF
oh no: Bun has crashed. This indicates a bug in Bun, not your code.
MartinWickman · 6 months ago

It crashed just when I ran /clear

❯ /clear

  ⎿  Tip: Use /permissions to pre-approve and pre-deny bash, edit, and MCP tools

─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
❯ 
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────  Opus 4.6 | ? | $0.00 | OutageService | feature/47478-internal-communication | default                                    Checking for updates
============================================================
Bun Canary v1.3.10-canary.63 (1979c945) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "claude"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(50) jsc spawn(40) standalone_executable process_dlopen yaml_parse(28)
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node:http2"
Elapsed: 208988ms | User: 2109ms | Sys: 1015ms
RSS: 0.56GB | Peak: 0.66GB | Commit: 0.76GB | Faults: 247495 | Machine: 0.14TB

panic(main thread): Segmentation fault at address 0xFFFFFFFFFFFFFFFF
oh no: Bun has crashed. This indicates a bug in Bun, not your code.
MagnusIIIBR · 6 months ago

Another....

`
============================================================
Bun v1.3.10 (1423d3c8) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "C:\Users\Nathan\.local\bin\claude.exe"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) abort_signal(4) fetch(101) jsc spawn(82) standalone_executable process_dlopen(2) yaml_parse(59)
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node:http2"
Elapsed: 98856ms | User: 5671ms | Sys: 2250ms
RSS: 0.85GB | Peak: 0.85GB | Commit: 1.26GB | Faults: 349138 | Machine: 42.62GB

panic(main thread): switch on corrupt value
oh no: Bun has crashed. This indicates a bug in Bun, not your code.`

MartinWickman · 6 months ago

It still crashes in version 2.1.47 :-(

Jerrybery · 6 months ago

Is this caused by bun's canary version's incoperation with Windows, or the issue just in 2.1.47?

Since my Claude Code goes well on Ubuntu with the same version, but crashes randomly on Windows.

mosjin · 6 months ago

New crash with claude code 2.1.50:

C:\Users\Administrator>claude --version
2.1.50 (Claude Code)

<img width="1908" height="475" alt="Image" src="https://github.com/user-attachments/assets/e0f41f7e-c350-42c2-9f82-dfe36b23805b" />

mosjin · 6 months ago

New crash:
C:\Users\Administrator>claude --version
2.1.50 (Claude Code)

<img width="1905" height="539" alt="Image" src="https://github.com/user-attachments/assets/c22e5d60-2d82-4f70-9dd5-3c98455ce328" />

ThatDragonOverThere · 6 months ago

Part of a Broader Bun v1.3.10 Crash Family

This segfault is one of 20+ Bun crash issues on Windows — different crash addresses (0x18, 0x7, 0x113, 0xFFFF), same root cause. 90+ unique users affected. Community root cause analysis (N-API race condition, 27 memory dumps, WinDbg traces) on #21875.

v2.1.53's 4 crash fixes didn't address the N-API issue. Still crashing on v2.1.55.

github-actions[bot] · 5 months ago

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

github-actions[bot] · 4 months ago

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.

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