SIGILL (Illegal Instruction) on Intel Xeon E3-1270 V2 (no AVX-512/AVX2 support) #12512

Description

Description:
When running the pre-built binary of OpenCode (version 1.1.53-1 from AUR), the application crashes immediately with a SIGILL (Illegal Instruction) error. This occurs on an Intel Xeon E3-1270 V2 CPU, which does not support AVX-512 or AVX2 instructions.

Steps to Reproduce:

1. Install opencode-bin from AUR (or download the pre-built binary).
2. Run opencode in a terminal.
3. The application crashes with:

   zsh: illegal hardware instruction (core dumped)  opencode
   

Debugging Output:

Using strace, the crash occurs at address 0x3cb1130 with:

--- SIGILL {si_signo=SIGILL, si_code=ILL_ILLOPN, si_addr=0x3cb1130} ---
+++ killed by SIGILL (core dumped) +++

Full strace output: [link to a gist or pastebin with the full log](https://gist.github.com/...).

System Information:

• CPU: Intel Xeon E3-1270 V2 (Ivy Bridge, no AVX-512/AVX2 support).
  Output of lscpu:

  Model name: Intel(R) Xeon(R) CPU E3-1270 V2 @ 3.50GHz
  Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm cpuid_fault epb pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts vnmi md_clear flush_l1d
  

• OS: Arch Linux (EndeavourOS), Kernel 6.18.2-1-cachyos-bore.
• Binary: /usr/bin/opencode (146 MiB, x86_64).

Analysis:

• The binary appears to include instructions not supported by older Intel CPUs (e.g., AVX-512 or AVX2).
• objdump -d /usr/bin/opencode | grep -E "avx512|avx2" returns no output, but strace confirms a SIGILL.
• All dependencies (libc, libicui18n.so.78, etc.) are correctly loaded.

Suggested Fixes:

1. Provide a binary compiled with -march=haswell or -march=ivybridge for compatibility with older CPUs.
2. Add a runtime CPU check to gracefully fail with a clear error message if unsupported instructions are required.
3. Document CPU requirements in the README (e.g., "AVX2 or newer required").

Workarounds Tried:

• Reinstalling opencode-bin (no change).
• Testing with a fresh user (no change).
• Updating all system libraries (no change).

Additional Notes:

• The issue does not occur on newer CPUs (e.g., Intel Skylake or AMD Zen 2+).
• Compiling from source with -march=native may resolve the issue, but a pre-built compatible binary would be ideal for users with older hardware.

Labels to Add (if possible):

• bug
• crash
• cpu-compatibility

Why This Matters:

Many users (especially on Linux) still rely on older but capable hardware (e.g., Xeon E3 v2/v3, i5/i7 3rd/4th gen). Providing a compatible binary or clear documentation would improve accessibility.

Let me know if you need further details or logs!

How to Submit:

1. Go to [OpenCode GitHub Issues](https://github.com/anomalyco/opencode/issues).
2. Click "New Issue", paste the above, and submit.

Note: If you want to attach the full strace log, upload it to [Gist](https://gist.github.com/) or [Pastebin](https://pastebin.com/) and link it in the issue.

Plugins

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OpenCode version

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Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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