Bun 1.3.14 segfault (SIGILL) on Linux x86_64 #33890

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1. github-actions

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   simonklee

   on Jun 25, 2026
2. github-actions commented on Jun 25, 2026

   

   github-actionsBot

   on Jun 25, 2026 – with GitHub Actions

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

   • Bundled OpenCode x64 binaries can crash with SIGILL / invalid opcode; baseline package may not be truly baseline #33595: Same SIGILL / invalid opcode crash class on Linux x64 with bundled Bun, including analysis of baseline vs modern binary packaging and AVX-512 instructions — closely related to the symptoms reported here.
3. tarsyc

   changed the title [-]Bun 1.3.14 segfault (SIGILL) on Linux x86_64 — AMD EPYC Zen4 (AVX-512)[/-] [+]Bun 1.3.14 segfault (SIGILL) on Linux x86_64[/+] on Jun 25, 2026
4. jjiangweilan commented on Jun 25, 2026

   

   jjiangweilan

   on Jun 25, 2026

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   same thing can happen on Windows 11
5. dmancilla85 commented on Jun 25, 2026

   

   dmancilla85

   on Jun 25, 2026

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   Same on Windows 11 24GB RAM i7-11
   Downgrading to v1.17.9 solve the issue in my case
6. simonklee commented on Jun 25, 2026

   

   simonklee

   on Jun 25, 2026

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   These windows issues are a different thing AFAIK. For that please try installing the last version that we just released v1.17.11

   👍React with 👍1Reacted by David A. Mancilla
7. cloph-dsp commented on Jun 25, 2026

   

   cloph-dsp

   on Jun 25, 2026

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   @simonklee can i safely update? will it work now?
8. JRedeker commented on Jun 27, 2026

   

   JRedeker

   on Jun 27, 2026

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   Additional data point: faulting IP disassembles to a deliberate ud2 panic, not an AVX/illegal-SIMD instruction

   • opencode 1.17.11 (latest), bundled Bun v1.3.14 (Linux x64 baseline)
   • WSL2 kernel 6.6.114.1-microsoft-standard-WSL2, Intel i7-12700K (avx2, no avx512), 41 GiB RAM (not OOM; 19 GiB free, load 1.68 at crash)
   • dmesg:

     traps: HeapHelper[...] trap invalid opcode ip:2607064 ... in opencode[24c8000+36e6000]
     opencode: HeapHelper: potentially unexpected fatal signal 4
     

   The binary is ET_EXEC, so the runtime IP maps 1:1 to the file. objdump -d at 0x2607064:

   2607045: e8 36 de 02 00   call 2634e80      # memset-loop helper (calls memset@plt)
   260705f: e8 1c de 02 00   call 2634e80
   2607064: 0f 0b            ud2               # <-- faulting IP
   2607066: cc               int3              # int3 padding (noreturn site)
   ...
   2607070: 55               push %rbp         # clean next-function prologue
   

   This is a deliberate panic/abort trap (ud2) on the Bun/JSC GC thread (HeapHelper), reached just after a memset/allocation helper — not a CPU-incompatible SIMD instruction. The binary embeds Rust panic machinery (std::panicking::begin_panic_handler, std::panicking::rust_panic_with_hook); ud2 is the standard Rust/Zig panic→abort trap.

   Triage note for the broader "invalid opcode" bucket (incl. #33595): a Bun/Zig ud2 panic produces the identical kernel trap invalid opcode / fatal signal 4 message as a genuine missing-AVX illegal instruction. The two are only distinguishable by disassembling the faulting IP. This instance is unambiguously a GC/runtime panic (this issue / #22084 bucket), not an AVX-baseline mismatch — the CPU here has no AVX-512 yet the binary is the baseline build, and the trapping byte is 0f 0b ud2, not an EVEX/zmm op.

   Reproduced on the latest 1.17.11, so the current release does not fix it. Crash recovered cleanly via process auto-restart; application state intact. Aggravating context: high concurrency (3+ primary sessions in one project + several vite dev servers) → elevated GC pressure on the HeapHelper thread.
9. github-actions commented on Aug 27, 2026

   

   github-actionsBot

   on Aug 27, 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.
10. github-actions

    closed this as not plannedon Aug 27, 2026