Description

Running opencode after npm install -g opencode-ai produces no output and exits silently with code 0 on x86_64 Linux systems that do not support AVX2 instructions.

Environment

• OS: Linux (Debian-based, glibc)
• Arch: x86_64 (no AVX2)
• Node: v24.13.1
• Package: opencode-ai (npm global install)
• opencode version: latest (0.0.55 at time of writing)

Steps to reproduce

1. On an x86_64 machine without AVX2: cat /proc/cpuinfo | grep avx2 returns nothing
2. npm install -g opencode-ai
3. Run opencode — no output, exits with code 0

Root cause

Two bugs compound to cause this:

1. Wrong binary selected during postinstall: postinstall.mjs resolves opencode-linux-x64 (no -baseline suffix) even on CPUs without AVX2. The correct package for non-AVX2 CPUs is
   opencode-linux-x64-baseline. The AVX2 check logic exists in the wrapper script bin/opencode but not in postinstall.mjs, so the wrong binary gets hard-linked to bin/.opencode.
2. Silent failure in wrapper: When the binary is killed by SIGBUS (due to an illegal instruction), spawnSync returns result.status = null. The wrapper then does:
   const code = typeof result.status === "number" ? result.status : 0
   process.exit(code)
3. null is not a number, so it exits with code 0 — no error, no output.

Workaround

Install using the official shell installer instead of npm:

curl -fsSL https://github.com/opencode-ai/opencode/releases/latest/download/opencode-linux-x86_64.tar.gz | tar xz -C ~/.local/bin

Or manually after npm install:

Download the correct baseline binary

curl -fsSL https://github.com/opencode-ai/opencode/releases/latest/download/opencode-linux-x86_64.tar.gz
| tar xz -C ~/.opencode/bin
export PATH="$HOME/.opencode/bin:$PATH"

Suggested fixes

1. In postinstall.mjs: mirror the AVX2 detection logic from bin/opencode to select the correct -baseline package on non-AVX2 x86_64 CPUs.
2. In bin/opencode: when result.signal is set (e.g. SIGBUS, SIGILL), print a diagnostic error and exit non-zero instead of silently exiting 0:
   if (result.signal) {
   console.error(opencode binary crashed with signal ${result.signal}. Your CPU may not support the required instructions.)
   process.exit(1)
   }

Plugins

No response

OpenCode version

No response

Steps to reproduce

1. On x86_64 machine without AVX2: confirm with grep avx2 /proc/cpuinfo (no output)
2. Install Node.js (e.g. via nvm): nvm install 24
3. npm install -g opencode-ai
4. Run opencode — no output, exits silently with code 0

To confirm the crash: strace -e trace=signal opencode 2>&1 | grep -E "SIGBUS|SIGILL" shows SIGBUS.

Screenshot and/or share link

No response

Operating System

Debian GNU/Linux 12 (Bookworm)

Terminal

tmux (screen-256color)