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Claude Code Issues / #86125

[BUG] Processus AMD A8-3800 supports SSE4.1/SSE4.2, but not AVX ni AVX2

Status Open
Reported on v2.1.227
Maintainer reply None cached
Activity 3 comments · opened Aug 12, 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?

Processus AMD A8-3800 supports SSE4.1/SSE4.2, but not AVX and not AVX2
AMD A8-3800, panic: Illegal instruction, claude.exe 2.1.227

What Should Happen?

Claude should be usable and not return
"
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Error Messages/Logs

2026-08-12 16:25:42 [info] [Lifecycle] Session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5: initializing → running
2026-08-12 16:25:42 [info] [FileWatching] Starting file watcher for session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5: C:\Users\laurent\AppData\Roaming\Claude\local-agent-mode-sessions\80544fe8-2e04-437a-a444-9c8500639b43\21a0b58b-a752-48dc-8315-48e782689845\local_21d8b21b-9963-447c-b47e-8044e7a0c1f5\outputs
2026-08-12 16:25:42 [info] [FileSystemWatcher] Started watching C:\Users\laurent\AppData\Roaming\Claude\local-agent-mode-sessions\80544fe8-2e04-437a-a444-9c8500639b43\21a0b58b-a752-48dc-8315-48e782689845\local_21d8b21b-9963-447c-b47e-8044e7a0c1f5\outputs for session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5
2026-08-12 16:25:42 [warn] [HostLoop] cli.js stderr: ============================================================

panic: Illegal instruction at address 0x7FF687709E55
panicked during a panic. Aborting.
2026-08-12 16:25:42 [error] Session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5 query error: Claude Code process exited with code 3. stderr: ============================================================

panic: Illegal instruction at address 0x7FF687709E55
panicked during a panic. Aborting. { telemetryMessage: 'Claude Code process exited with code 3', errorClass: 'process_exited_nonzero', exitCode: 3, stack: 'Error: Claude Code process exited with code 3. stderr: ============================================================\n\npanic: Illegal instruction at address 0x7FF687709E55\npanicked during a panic. Aborting.\n    at ZJ.getProcessExitError (C:\\Program Files\\WindowsApps\\Claude_1.28929.0.0_x64__pzs8sxrjxfjjc\\app\\resources\\app.asar\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:10754)\n    at ChildProcess.n (C:\\Program Files\\WindowsApps\\Claude_1.28929.0.0_x64__pzs8sxrjxfjjc\\app\\resources\\app.asar\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:14948)\n    at Object.onceWrapper (node:events:631:26)\n    at ChildProcess.emit (node:events:521:24)\n    at m (C:\\Program Files\\WindowsApps\\Claude_1.28929.0.0_x64__pzs8sxrjxfjjc\\app\\resources\\app.asar\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:4581)\n    at ChildProcess.<anonymous> (C:\\Program Files\\WindowsApps\\Claude_1.28929.0.0_x64__pzs8sxrjxfjjc\\app\\resources\\app.asar\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:4771)\n    at Object.onceWrapper (node:events:631:26)\n    at ChildProcess.emit (node:events:521:24)\n    at ChildProcess._handle.onexit (node:internal/child_process:295:12)' }
2026-08-12 16:25:42 [info] [Lifecycle] Session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5: running → idle
2026-08-12 16:25:42 [info] [FileWatching] Stopping file watcher for session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5
2026-08-12 16:25:42 [info] [FileSystemWatcher] Stopped watching for session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5
2026-08-12 16:25:42 [info] [CycleHealth] Unhealthy cycle: {
  session_id: 'local_21d8b21b-9963-447c-b47e-8044e7a0c1f5',
  scheduled_task_id: null,
  variant_key: '06_22_2026.replace',
  session_built_prompt: true,
  space_id: undefined,
  session_type: undefined,
  parent_session_id: undefined,
  host_loop_mode: true,
  vm_instance_id: '7c717c00-d01d-413f-b122-4c4134dc272e',
  model: 'claude-sonnet-5',
  permission_mode: null,
  cli_session_id: null,
  user_message_uuid: '93807608-9638-4d87-9b44-80894b5599da',
  cycle_health: 'unhealthy',
  had_first_response: false,
  seconds_to_outcome: 1,
  is_resume: false,
  unhealthy_reason: 'system_error',
  error_message: 'Claude Code process exited with code 3. stderr: ============================================================\n' +
    '\n' +
    'panic: Illegal instruction at address 0x7FF687709E55\n' +
    'panicked during a panic. Aborting.',
  error_category: 'process_crashed',
  transcript_size_bytes: undefined,
  msix_identity_source: 'native_ok',
  msix_fs_virtualized: true,
  cli_binary_source: 'required_version',
  probe_child_virtual_view: 'pending'
}
2026-08-12 16:25:42 [error] Sentry caught: {
  eventId: '289118c183e242acb52ed6258dd24eaf',
  type: 'Error',
  value: 'Claude Code process exited with code 3. stderr: ============================================================\n' +
    '\n' +
    'panic: Illegal instruction at address 0x7FF687709E55\n' +
    'panicked during a panic. Aborting.',
  stack: 'Error: Claude Code process exited with code 3. stderr: ============================================================\n' +
    '\n' +
    'panic: Illegal instruction at address 0x7FF687709E55\n' +
    'panicked during a panic. Aborting.\n' +
    '    at ZJ.getProcessExitError (app://\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:10754)\n' +
    '    at ChildProcess.n (app://\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:14948)\n' +
    '    at Object.onceWrapper (node:events:631:26)\n' +
    '    at ChildProcess.emit (node:events:521:24)\n' +
    '    at m (app://\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:4581)\n' +
    '    at ChildProcess.<anonymous> (app://\\.vite\\build\\index2.chunk-DiaQ9Xz9.js:95:4771)\n' +
    '    at Object.onceWrapper (node:events:631:26)\n' +
    '    at ChildProcess.emit (node:events:521:24)\n' +
    '    at ChildProcess._handle.onexit (node:internal/child_process:295:12)'
}
2026-08-12 16:25:42 [info] [MsixSpawnDiag] probe result: visible
2026-08-12 16:25:43 [warn] Transcript not found for session local_21d8b21b-9963-447c-b47e-8044e7a0c1f5 (cliSessionId: none)

Steps to Reproduce

It seems only with a AMD A8-3800

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Version 1.28929.0 (d1a6bc)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_

View original on GitHub ↗

3 Comments

genose · 1 month ago

For users hitting this on Linux or wanting to build from source, there is a community source build that explicitly targets no-AVX2 / SSE4.2-only CPUs (x5690, AMD A8-3800, older Xeons, etc.):

👉 https://github.com/genose\/claude-code-source-build-community-edition-noAVX-foroldtimer

What was fixed vs the upstream source:

  • Forces the baseline bun binary (@oven/bun-*-baseline) at build time — no AVX2 required by the builder
  • Auto-detects and prefers baseline bun via optionalDependencies on npm install
  • Fixes a null stderr crash when bun is missing (reconcileBuildErrors)
  • Adds a clear actionable error when bun is not found

Usage:

git clone https://github.com/genose\/claude-code-source-build-community-edition-noAVX-foroldtimer
cd claude-code-source-build
npm install   # pulls baseline bun automatically based on /proc/cpuinfo
node scripts/build-cli.mjs

The output cli.js runs under system Node.js which has no AVX2 requirement.

The root issue remains: Anthropic should ship a baseline binary for the official distribution. The detection logic already exists in bun's own npm installer (isLinuxAVX2() reads /proc/cpuinfo) — it just isn't applied to the distributed claude.exe / CLI runner.

---
Quick install (installs as claudius command):

macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer/noavx_esbuild/install.sh | bash

Windows (PowerShell):

irm https://raw.githubusercontent.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer/noavx_esbuild/install.ps1 | iex
claudius --version output: `` 2.1.88 (Claude Code — Community Edition no-AVX / old-timer) Patched by genose.org · github.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer Assisted by a custom no-AVX build of Claude Code itself — cheers Anthropic, heavily paid to drop old-timer CPU support 👴🖥️ ``

Fork PR (docs): https://github.com/genose/claude-code/pull/1

genose · 1 month ago

Same root cause — the AMD A8-3800 (Llano, 2011) supports SSE4.1/SSE4.2 but not AVX, so the bundled bun binary crashes.

I’m running on an Intel Xeon X5690 with the same problem (no AVX at all) and built a fix that replaces bun with esbuild — a pure Go binary with no AVX requirement:

Repo: https://github.com/genose\/claude-code-source-build-community-edition-noAVX-foroldtimer (branch: noavx_esbuild)

Works on macOS, Linux, and Windows. Bun officially publishes *-baseline builds that don’t require AVX — Anthropic just needs to ship that variant instead of the AVX-optimized one. Both AMD pre-Bulldozer and Intel pre-Sandy Bridge CPUs are affected.

---
Quick install (installs as claudius command):

macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer/noavx_esbuild/install.sh | bash

Windows (PowerShell):

irm https://raw.githubusercontent.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer/noavx_esbuild/install.ps1 | iex
claudius --version output: `` 2.1.88 (Claude Code — Community Edition no-AVX / old-timer) Patched by genose.org · github.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer Assisted by a custom no-AVX build of Claude Code itself — cheers Anthropic, heavily paid to drop old-timer CPU support 👴🖥️ ``

Fork PR (docs): https://github.com/genose/claude-code/pull/1

genose · 16 days ago

If you are hitting this because Bun requires AVX and your CPU / VM does not have it, the Claude Code Community Edition no-AVX fork exists for exactly this situation.

It rebuilds Claude Code using Node.js + esbuild instead of Bun, so it runs on any CPU without AVX/AVX2 — bare metal, VMs, VPS, OpenStack, Proxmox KVM, Hyper-V, VirtualBox, QEMU, old Xeons, AMD pre-Bulldozer, all of it. One-line install:

curl -fsSL https://raw.githubusercontent.com/genose/claude-code-source-build-community-edition-noAVX-foroldtimer/noavx_esbuild/install.sh | bash

Currently at v2.1.283. The binary is called claudius (with a claude symlink for IDE/VS Code compat).

Honest note: the version number tracks upstream so the API gate passes, but the underlying app code is frozen at the v2.1.88 era — upstream switched to Bun-compiled bytecode at v2.1.126 and source maps are no longer obtainable. What you get: a working Node.js build that runs on your hardware, with fresh npm dependency packages at build time.

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