Claude Code v2.1.241 native binary crashes with SIGILL on CPUs without SSE4.1

Description

Claude Code v2.1.241's claude.exe native binary crashes immediately with SIGILL (Illegal Instruction) on CPUs that lack SSE4.1 support. This affects both the CLI and the VS Code extension (which uses the same binary).

Previous versions (v2.1.92) used a Node.js cli.js entrypoint and worked fine on these CPUs.

Environment

• OS: Ubuntu 24.04, Linux 6.8.0-136-generic, x86_64
• CPU: Intel Xeon 5130 (supports up to SSSE3, no SSE4.1)
• Claude Code version: 2.1.241
• Installation: npm (@anthropic-ai/claude-code)

Steps to Reproduce

1. Install Claude Code v2.1.241 on a machine with a pre-Penryn CPU (no SSE4.1)
2. Run claude or launch the VS Code extension

Crash Details

Signal: 4 (ILL)

GDB shows the faulting instruction:

0x1b8fe99: pinsrq $0x0,%rsi,%xmm1

pinsrq requires SSE4.1 per the Intel instruction reference. This CPU's flags (sse sse2 ssse3) do not include sse4_1.

Kernel log confirms:

traps: claude.exe[...] trap invalid opcode ip:1b8fe99 sp:... error:0 in claude.exe[19a5000+3b58000]

Expected Behavior

Either:

• Provide a binary compiled without SSE4.1 (baseline x86_64 / SSE2)
• Restore the Node.js cli.js entrypoint as a fallback
• Document the minimum CPU requirement

Workaround

Staying on v2.1.92, which used cli.js and works on this CPU.