[BUG] Bus error (SIGBUS) on AlmaLinux 9 / RHEL 9 with kernel 5.14 — ARCH_SET_XCOMP_PERM syscall not supported

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code crashes immediately with "Bus error (core dumped)" on AlmaLinux 9.7
running kernel 5.14. The crash occurs before any useful work is done, even with
claude --help. The binary crashes whether run from NFS home directory or local
/tmp storage.

What Should Happen?

Claude Code should run successfully on AlmaLinux 9 / RHEL 9, which is a fully
supported enterprise Linux distribution. RHEL 9's standard kernel is 5.14 and
will remain so for its entire lifecycle — this affects all standard RHEL 9 and
AlmaLinux 9 installations that have not applied a custom kernel.

Error Messages/Logs

$ claude --help
Bus error (core dumped)

$ strace ~/.local/bin/claude --help 2>&1 | head -10
execve("/tmp/claude-jkurtzwe", ["/tmp/claude-jkurtzwe", "--help"], 0x7ffd26ec0168 /* 68 vars */) = 0
brk(NULL)                               = 0xf483000
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc97749c20) = -1 EINVAL (Invalid argument)
--- SIGBUS {si_signo=SIGBUS, si_code=BUS_ADRERR, si_addr=0x61c8000} ---
+++ killed by SIGBUS (core dumped) +++

$ ldd ~/.local/bin/claude
ldd: exited with unknown exit code (135)

Steps to Reproduce

1. SSH into a machine running AlmaLinux 9.7 with kernel 5.14.x (standard RHEL 9 kernel)
2. Run the official installer: curl -fsSL https://claude.ai/install.sh | bash
3. Run: claude --help
4. Observe: Bus error (core dumped)

Confirmed system details:

• OS: AlmaLinux 9.7
• Kernel: 5.14.0-611.55.1.el9_7.x86_64
• CPU flags confirmed present: avx, avx2 (not a CPU instruction issue)
• /tmp is local disk (not NFS) — crash occurs regardless of binary location
• Architecture: x86_64, Virtual: kvm

The bundled Node.js binary calls arch_prctl(0x3001), which is ARCH_SET_XCOMP_PERM —
a syscall for enabling AMX (Advanced Matrix Extensions) CPU features added in kernel
5.16. RHEL 9 / AlmaLinux 9 ship with kernel 5.14 as their stable base and will not
update to 5.16+. The kernel returns EINVAL, which causes an immediate SIGBUS crash.

This affects all standard RHEL 9 / AlmaLinux 9 systems, which represent a large
portion of enterprise and HPC Linux deployments.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.150 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Terminal.app (macOS)

Additional Information

This was reproduced on a Fermilab CMS LPC computing cluster (cmslpc.fnal.gov),
which is representative of a broad class of HPC/scientific computing environments
that run standard RHEL 9 or AlmaLinux 9.

Suggested fix: the bundled Node.js should handle EINVAL from ARCH_SET_XCOMP_PERM
gracefully rather than crashing, or Claude Code should ship with a Node.js build
that does not make this call on kernels that don't support it. Node 18 LTS does not
make this call and is unaffected.