SIGILL (ILL_ILLOPN) on bb binary init — Intel Haswell, AVX2 present, AVX-512 absent

[piotrhanusiak]

What are you trying to do?

Run local network using: aztec start --local-network

Code Reference

strace ~/.aztec/versions/4.3.1/node_modules/@aztec/bb.js/build/amd64-linux/bb 2>&1 | tail -3

Output:
--- SIGILL {si_signo=SIGILL, si_code=ILL_ILLOPN, si_addr=0x58a5328cf60f} ---
+++ killed by SIGILL (core dumped) +++

Aztec Version

4.3.1

OS

Ubuntu 24.04 LTS

Browser (if relevant)

No response

Node Version

24.12.0

Additional Context

CPU: Intel Core i5-4300U (Haswell, 2013)
CPU flags present: AVX, AVX2, BMI1, BMI2, ADX, FMA, SSE4.1, SSE4.2
CPU flags absent: AVX-512

ILL_ILLOPN means the CPU recognizes the instruction but cannot execute it with the given operand. This is the signature of AVX-512 or post-Haswell specific compilation flags in the bb binary.

Crash happens at binary initialization — before any proof is attempted. All standard ZK instruction requirements (AVX2, BMI2, ADX) are present on this machine.

Question: what is the actual minimum CPU microarchitecture required? This is not documented anywhere in the installer or getting started guide.