[BUG] npm install now ships Bun binary (v2.1.126) — npm workaround for non-AVX VPS is dead, no upgrade path

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/51976
2. https://github.com/anthropics/claude-code/issues/50384
3. https://github.com/anthropics/claude-code/issues/33153

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🤖 Generated with Claude Code

This is NOT a duplicate. The linked issues (#51976, #50384, #33153) describe the original AVX/Bun crash. My issue documents a NEW regression: as of v2.1.x, the npm installation path — which was the recommended workaround in ALL those issues — now ALSO ships a Bun ELF binary. The documented workaround is dead and there is no upgrade path for non-AVX environments.

Additionally, downgrading to the last Node.js-based version (2.0.62-2.0.76) no longer works because these versions are incompatible with the current API.

This is a escalation of the original problem, not a duplicate.

Same issue. We're not able to expose AVX for security reasons on our VMs. We're forced to use a much older model with reduced functionality until this is fixed.

I open ticket to get help. Only AI mail comes back and nothing happens.

Why closed

Why is this closed... it is not resolved and I have the same issue.

Same issue here. My use case is to build a Docker container with Claude Code pinned to a specific version, which devs can use for remote development:

 > [2/2] RUN set -eux;     npm install -g "@anthropic-ai/claude-code@2.1.140";     npm cache clean --force;     claude --version:
36.91 CPU lacks AVX support. Please consider upgrading to a newer CPU.

v2.1.112 works. Curiously, upgrading a v2.1.112 install to v2.1.140 also seems to work on non-AVX CPU.

Same issue here.

I made a new discovery. Installing and running Claude Code natively (using the recommended curl -fsSL https://claude.ai/install.sh | bash) seems to work on non-AVX system, as long as AES instructions are available. The error message given by bun is misleading. The issue in my case was that the VM I was using had qemu64 as a CPU type, which lacks all modern instructions. Switching it to x86-64-v2-AES or host resolved the issue.

And it is possible to install a specific native version by appending the version to the install command: curl -fsSL https://claude.ai/install.sh | bash 2.1.153 installs v2.1.153.

same

The break is precisely at 2.1.113, not a gradual regression — and the package internals confirm there is no JS fallback left.

What changed:

• 2.1.112: bin = { "claude": "cli.js" } — ships the full bundled-JS app. This is the last version that runs on non-AVX CPUs.
• 2.1.113: bin = { "claude": "bin/claude.exe" }, and the per-platform optionalDependencies switched from @img/sharp-* to @anthropic-ai/claude-code-<platform>. Per the 2.1.113 changelog: "Changed the CLI to spawn a native Claude Code binary (via a per-platform optional dependency) instead of bundled JavaScript."

cli.js is gone from 2.1.113+. Unpacking the wrapper package (~148K) shows only three files of interest:

• bin/claude.exe — a shell stub that just prints "Error: claude native binary not installed"
• cli-wrapper.cjs — labeled a "fallback launcher" but contains no app; it only spawnSyncs the native binary
• install.cjs — postinstall that links the per-platform native binary

So the "optional dependency" wording only controls delivery of the native binary — it does not preserve a JavaScript runtime path. Every code path on 2.1.113+ ends at the native binary, and a comment in both cli-wrapper.cjs and install.cjs confirms the requirement: "the x64 build needs AVX, which Rosetta doesn't emulate."

Net: there is no env var or flag to force the old JS app on 2.1.113+, because that code is no longer published in the npm package. The only real fix is shipping a baseline/non-AVX claude-code-linux-x64 build. Confirmed on a no-AVX host: 2.1.112 is a hard ceiling.

Suggestion: Ship both AVX + baseline builds with runtime auto-detection

First, thank you for Claude Code — it's genuinely transformed how we build and ship software. This is a feature request more than a bug report, and we think it could unlock a significant new segment of users.

The opportunity:
A large portion of VPS and virtualized environments (Proxmox KVM with default kvm64, OpenStack, Docker, LXC) don't expose AVX to guests by default. These are incredibly common setups for developers who want to run Claude Code autonomously on a server — arguably one of the most exciting use cases for Claude Code.

The good news — Bun already solved this upstream:
Bun officially publishes and maintains baseline builds without AVX dependency:

• bun-linux-x64 → current (AVX required)
• bun-linux-x64-baseline → no AVX required

Proposed approach — ship both, auto-detect at install:
\\\js
// postinstall.cjs
if (cpuHasAVX()) {
installBinary('claude-code-linux-x64') // current behavior, unchanged
} else {
installBinary('claude-code-linux-x64-baseline') // baseline, no AVX
}
\\\

Why this is a zero-tradeoff win:

• AVX users → identical binary, zero change, zero performance loss
• Non-AVX users → fully unblocked, same features
• Performance difference on baseline is ~5–15% on CPU-bound ops — negligible since Claude Code's real bottleneck is always API latency, not local compute

Current workaround and its limits:
Pinning to 2.1.112 works today but it's a dead end — users are frozen with no upgrade path as features and models evolve.

Since Bun already maintains these baseline builds officially, the implementation cost is a CI pipeline addition rather than a new engineering effort. We'd love to see this on the roadmap — it would open Claude Code's autonomous server workflow to a huge number of developers who are genuinely excited to use it that way.

Happy to help test or provide environment details if useful!

I'm too stuck with 2.1.112 on a VPS, they're not going to support AVX on such environments. Looking forward to any workaround, hoping in a fix on Anthropic's side

Please save our old CPUs. They still have plenty of life left. 🙏

Adding another confirmation — this time from a bare-metal, non-AVX physical CPU (not a VM/VPS), with a full descending bisect of every published npm release.

Environment

• OS: openSUSE Linux
• Kernel: 6.4.0-150600.23.103-default
• Architecture: x86_64
• CPU: AMD Athlon II X4 645 Processor
• CPU features: no AVX and no AVX2
• Node.js: v22.23.1
• npm: 10.9.8
• Installation method: npm package @anthropic-ai/claude-code

Reproduction and exact compatibility boundary

I pulled the complete published version list directly from the npm registry (467 releases) and tested versions in descending semantic-version order using an isolated npm prefix. The 2.1.112 → 2.1.113 boundary is exact:

| Version | native_status | bin_target | Node cli.js entry? |
|---|---|---|---|
| 2.1.112 | WORKS (exit 0) | cli.js | yes |
| 2.1.113 | SIGILL (exit 132) | bin/claude.exe | no (NO_NODE_ENTRY) |
| 2.1.114 … 2.1.215 | SIGILL (exit 132) | bin/claude.exe | no |

Totals across the bisect:

• Versions tested: 88
• SIGILL versions: 87 consecutive releases (every published version newer than 2.1.112)
• npm installation succeeded for every tested release (0 install failures)
• Other failure types: 0

So the regression isn't just "Bun requires AVX" — 2.1.113 also removes the Node.js cli.js fallback that 2.1.112 still ships. On this machine there is no way to invoke any release > 2.1.112 through Node.

Working output on 2.1.112 (both invocation methods):

$ node_modules/.bin/claude --version
2.1.112 (Claude Code)
$ node node_modules/@anthropic-ai/claude-code/cli.js --version
2.1.112 (Claude Code)

Failing output on every newer release, even for --version:

Illegal instruction (core dumped)

The crash happens before authentication, project loading, or any normal CLI operation.

Workaround that did not help

BUN_JSC_useJIT=0 claude --version

Still terminates with Illegal instruction (core dumped) — so disabling the JSC JIT does not recover non-AVX compatibility on the bundled Bun binary.

Adding another data point — macOS on bare-metal Intel, confirming the boundary is AVX2 (not AVX1) and that the regression is not Linux-specific.

Environment

• OS: macOS 14.7.8 (Sonoma), build 23H730
• Architecture: x86_64
• CPU: Intel Core i7-3820QM (Ivy Bridge, 2012)
• CPU features: AVX1.0 present, AVX2 absent
• Node.js: v25.2.1
• npm: 11.6.2
• Installation: npm package @anthropic-ai/claude-code

Exact boundary

$ npm install -g @anthropic-ai/claude-code@2.1.112
$ claude --version
2.1.112 (Claude Code)          # works

$ npm install -g @anthropic-ai/claude-code@2.1.113
$ claude
Illegal instruction: 4          # SIGILL, before any CLI work

Same 2.1.112 → 2.1.113 cliff as the Linux reports above. Since this CPU has AVX1 but not AVX2, the Bun baseline swap needs to target AVX2, not AVX — otherwise every pre-Haswell Intel Mac (all pre-mid-2013 models) stays broken alongside the Linux VPS cases.