Repository navigation
[BUG] Illegal instruction crash on CPUs without AVX after 2.1.112 (native binary regression) #50384
Description
Preflight Checklist
- I have searched existing issues and this hasn't been reported yet
- This is a single bug report (please file separate reports for different bugs)
- I am using the latest version of Claude Code
What's Wrong?
Starting from version 2.1.113, the CLI crashes immediately with "Illegal instruction".
Version 2.1.112 works correctly in the same environment.
This regression appears to coincide with the change to spawning a native binary instead of running bundled JavaScript.
The issue is likely caused by the native binary requiring CPU instructions (e.g. AVX/AVX2) that are not available on older CPUs.
What Should Happen?
The CLI should start normally.
If the system CPU does not support required instructions, the CLI should:
- either provide a compatible baseline binary (no AVX requirement), or
- gracefully fall back to a compatible implementation instead of crashing.
Error Messages/Logs
Illegal instructionSteps to Reproduce
-
Install latest version:
npm install -g @anthropic-ai/claude-code@2.1.113 -
Run:
claude --version -
Observe crash:
Illegal instruction
Claude Model
None
Is this a regression?
Yes, this worked in a previous version
Last Working Version
2.1.112
Claude Code Version
2.1.113
Platform
Anthropic API
Operating System
Ubuntu/Debian Linux
Terminal/Shell
VS Code integrated terminal
Additional Information
CPU:
AMD A4-3310MX APU (older CPU without AVX/AVX2 support)
Relevant CPU flags:
sse, sse2, sse4a (NO avx / avx2)
Environment:
- Running inside Docker container
- Node.js v24.13.0
- npm 11.6.2
Key observation:
Version 2.1.112 works correctly, but 2.1.113+ crashes immediately.
This strongly suggests the newly introduced native binary is compiled with CPU instructions not supported on older hardware.
Suggested fix:
- Provide a baseline x86_64 build without AVX requirements, or
- Detect CPU capabilities at runtime and provide a fallback
Activity
github-actions commentedon Apr 18, 2026
Found 3 possible duplicate issues:
invalid opcodeon non-AVX CPUs (same as fixed #19907) #37277This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
gcampaner commentedon Apr 18, 2026
Confirming the same regression on macOS Intel (Mac mini, x86_64) — not only Linux.
Environment
npm install -g @anthropic-ai/claude-codeSymptom
No output, no stack trace — SIGILL immediately on launch.
Versions tested
Root cause (matches this issue + #50190 + #33153)
v2.1.113 switched to a native per-platform binary. That binary appears to be compiled with AVX/AVX2 as baseline, breaking older Intel Macs and any non-AVX x86_64 host. Since the native binary is bundled inside the npm package, there is no user-side workaround (swapping
bun-baselineglobally doesn't help — CC uses its own embedded binary, as documented in #33153).Workaround
Pin to 2.1.112 and disable auto-updater:
npm install -g @anthropic-ai/claude-code@2.1.112 export DISABLE_AUTOUPDATER=1Request
Please ship a baseline x86_64 native binary (no AVX requirement) or fall back to the bundled JS path when the host CPU lacks AVX2. The same class of regression was previously fixed after #19907 / #20019 — the fix just needs to survive the move to native binaries.
neverbot commentedon Apr 18, 2026
Confirming on Intel Core 2 Duo P7550 (MacBook Pro running NixOS). CPU flags include
sse4_1but lacksse4_2,popcntandavx— belowx86-64-v2.Bisection: 2.1.100/107/110/112 work, 2.1.113 and 2.1.114 crash with
Illegal instruction (core dumped). Workaround confirmed:npm install -g @anthropic-ai/claude-code@2.1.112+"autoUpdates": falsein~/.claude/settings.json.+1 for a baseline x86_64 build or JS fallback when AVX is missing.
[-][BUG] Illegal instruction crash on CPUs without AVX after 2.1.111 (native binary regression)[/-][+][BUG] Illegal instruction crash on CPUs without AVX after 2.1.112 (native binary regression)[/+]hibbes commentedon Apr 19, 2026
For anyone who needs to stay on a current Claude Code version despite this regression, I posted a Node-only workaround over in #37065 — extracts the JS bundle from the
.bunELF section of@anthropic-ai/claude-code-linux-x64and runs it under system Node, no Bun needed. Verified on Core 2 Duo P7350 (SSE4.1, no SSE4.2/POPCNT/AVX) with 2.1.114 — full TUI, MCP, skills, Glob/Grep. Not a replacement for an upstream fix (aCLAUDE_CODE_FORCE_NODE_FALLBACK=1env ininstall.cjs+cli-wrapper.cjswould be the clean one-liner), but it unblocks users in the meantime.jhardin-accumula commentedon Apr 22, 2026
@hibbes - does your workaround work with 2.1.117+? There was a serious problem regarding context handling in Opus 4.7 fixed in that release...
hibbes commentedon Apr 23, 2026
@jhardin-accumula Yes — confirmed working on 2.1.117. I'm running it on my Core 2 Duo P7350 right now (
claude-node --version→2.1.117 (Claude Code)), and the Opus 4.7 context-window fix is live (/contextreports correctly, autocompact no longer fires at ~200K).For anyone re-running the extraction against 2.1.117, the bundle changed slightly vs. 2.1.116 and needs three small tweaks in the update script:
function(exports, require, module, …)) — replace fixed-string check with a regex allowing[[:space:]]*.ajv/dist/runtime/…,fs/promises,path/posix,stream/consumers,timers/promises) get flagged as missing even though the root packages are declared. Reduce to the first path component (or@scope/name) before checkingpackage.json; allow node-builtin subpaths via(/.*)?$.grep -oEonly returns non-overlapping matches, so a secondBun.Xinside the same guarded block was being missed. Rewrote in Python with per-occurrence ±200-char windowing; also catchestypeof globalThis.BunandBun?.-optional chains.New guarded-via-
typeofBun call sites verified in 2.1.117 (all safe, no shim needed):Bun.gc,Bun.JSONL,Bun.stringWidth,Bun.which,Bun.embeddedFiles,Bun.hash,Bun.stripANSI,Bun.wrapAnsi,Bun.generateHeapSnapshot. The only ungarded Bun calls are stillBun.spawn/Bun.listen/Bun.Transpiler, all inside try/catch and never triggered in practice.Still believe the proper fix is upstream — a
CLAUDE_CODE_FORCE_NODE_FALLBACK=1env honored ininstall.cjs+cli-wrapper.cjswould kill the whole class of pre-AVX2 CPU regressions without bundling a second binary. But in the meantime: yes, current main works, and you get the Opus 4.7 context fix.github-actions commentedon May 27, 2026
Closing for now — inactive for too long. Please open a new issue if this is still relevant.
github-actions commentedon Jul 24, 2026
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.