opencode exits immediately with Illegal instruction on WSL2/Linux (ACP unusable) #18411

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1. github-actions

   assigned

   rekram1-node

   on Mar 20, 2026
2. github-actions

   added

   coreAnything pertaining to core functionality of the application (opencode server stuff)Anything pertaining to core functionality of the application (opencode server stuff)

   windows

   on Mar 20, 2026
3. github-actions commented on Mar 20, 2026

   

   github-actionsBot

   on Mar 20, 2026 – with GitHub Actions

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   This issue might be a duplicate of existing issues. Please check:

   • zsh: illegal hardware instruction opencode #8345: Same "illegal hardware instruction" error with opencode
   • SIGILL (Illegal Instruction) on Intel Xeon E3-1270 V2 (no AVX-512/AVX2 support) #12512: SIGILL (Illegal Instruction) on CPU without AVX/AVX2 support — likely the same root cause
   • [FEATURE]: Support for Legacy CPUs (Non-AVX) - SIGILL error on Intel Pentium E5300 #18390: SIGILL error on non-AVX CPU, feature request for legacy CPU support
   • SIGILL on Intel Celeron J3455 (no AVX/AVX2) in OpenCode 1.1.64; older revision works #13432: SIGILL on Intel Celeron (no AVX/AVX2) — same class of issue
   • [Bug] OpenCode TUI freezes intermittently on WSL2 (input buffered), traced to Node.js v25.8 JIT generating SIGILL causing WSL kernel crashes #18132: WSL2 + SIGILL combination causing opencode to fail — very similar environment and symptoms

   The common thread across these issues is that opencode's bundled Bun binary requires AVX/AVX2 CPU instructions, and environments lacking those (including some WSL2 setups or older CPUs) crash with Illegal instruction. Please check if any of these match your situation before this issue proceeds.

   👀React with 👀1Reacted by George Lester
4. thdxr

   removed

   windows

   coreAnything pertaining to core functionality of the application (opencode server stuff)Anything pertaining to core functionality of the application (opencode server stuff)

   on May 3, 2026
5. github-actions commented on Jul 4, 2026

   

   github-actionsBot

   on Jul 4, 2026 – with GitHub Actions

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   To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.
6. github-actions

   closed this as not plannedon Jul 4, 2026
7. glepretre commented on Jul 6, 2026

   

   glepretre

   on Jul 6, 2026

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   Another unresolved legitimate issue closed by a bot
8. Knetic commented on Sep 15, 2026

   

   Knetic

   on Sep 15, 2026

   Last edited by Knetic

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   The common thread across these issues is that opencode's bundled Bun binary requires AVX/AVX2 CPU instructions

   The bot at least did find the issue in my case , and this is a dupe of other issues - I'm using a very old core2 duo proc, and bun's decision to require amd64v3+ means that my cpu platform can't use it.
   This is odd, since afaik every native language (go/gcc/clang/nim/d/rust/etc) default to emitting amd64v1 binaries, unless a distro or user explicitly says to use a different variant (which is uncommon). Not something opencode can change, it's another flaw with Bun.

   Since this is the top search result, i'll mention i tried what was suggested in this previous thread (use mainline from releases page) which didn't work - same error.
   There is a fork of bun+opencode that addresses this issue.

   What i did was follow this guy's path, which was to use a different harness entirely that doesn't have this problem.