[BUG] Claude Code crashes on CPUs without AVX support since recent update

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?

Claude Code was working fine until yesterday. Today it crashes immediately with "Illegal instruction" error.

What Should Happen?

Environment:

• Linux (Ubuntu)
• CPU without AVX support
• Claude Code v2.1.15
• Was working before the latest update

Expected behavior:
Claude Code should work on CPUs without AVX, as it did before.

Error Messages/Logs

olimpuss@player:~$ claude
============================================================
Bun v1.3.6 (d530ed99) Linux x64 (baseline)
Linux Kernel v6.8.0 | glibc v2.39
CPU: sse42 popcnt
Args: "claude"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(16) jsc no_avx2 no_avx spawn(11) standalone_executable
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:domain" "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:querystring" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node-fetch" "node:inspector" "node:http2" "node:diagnostics_channel"
Elapsed: 1914ms | User: 1106ms | Sys: 272ms
RSS: 1.23GB | Peak: 0.40GB | Commit: 1.23GB | Faults: 0 | Machine: 6.11GB

CPU lacks AVX support. Please consider upgrading to a newer CPU.
panic(main thread): Illegal instruction at address 0x4001FB4
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/1.3.6/B_1d530ed9GugogigD+ypR_s1nggE_____________msnt/DwujpiFkqjykEyhny/CA3Ao7vggE

Steps to Reproduce

olimpuss@player:~$ sudo npm install -g @anthropic-ai/claude-code@2.0.77 --force
npm WARN using --force Recommended protections disabled.

changed 5 packages in 4s

4 packages are looking for funding
run npm fund for details
olimpuss@player:~$ claude

▐▛███▜▌ Claude Code v2.1.15
▝▜█████▛▘ Sonnet 4.5 · API Usage Billing
▘▘ ▝▝ /home/olimpuss

───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
❯ /
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Missing API key · Run /login
============================================================
Bun v1.3.6 (d530ed99) Linux x64 (baseline)
Linux Kernel v6.8.0 | glibc v2.39
CPU: sse42 popcnt
Args: "claude"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(31) jsc no_avx2 no_avx spawn(11) standalone_executable process_dlopen
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:domain" "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:querystring" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node-fetch" "node:inspector" "node:http2" "node:diagnostics_channel"
Elapsed: 8380ms | User: 1717ms | Sys: 345ms
RSS: 1.23GB | Peak: 0.43GB | Commit: 1.23GB | Faults: 6 | Machine: 6.11GB

CPU lacks AVX support. Please consider upgrading to a newer CPU.
panic(main thread): Illegal instruction at address 0x4001FB4
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/1.3.6/B_1d530ed9mgEugogigD+ypR____s1nggEs1nggE____wyo1/D________A3Ao7vggE

Illegal instruction (core dumped)

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

v2.1.15

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_