halscope segfaults on Raspberry Pi 4

[alangibson]

Here are the steps I follow to reproduce the issue:

1. Install LinuxCNC on a Raspberry Pi 4 using https://forum.linuxcnc.org/9-installing-linuxcnc/47662-installing-linuxcnc-2-9-on-raspberry-pi-4-with-preempt-rt-kernel
2. Start linuxcnc with QtPlasmaC ui on a Raspberry Pi 4
   3a. Click on SETTINGS then HAL SCOPE
   3b. or open a terminal and run halscope
3. Observe that halscope crashes

This is what I expected to happen:

halscope runs without crashing

This is what happened instead:

alangibson@linuxcnc:~ $ halscope
halscope: config file 'autosave.halscope' could not be opened
hal/utils/scope.c Caught signum=11 <Segmentation fault>
   killing userspace comp_id=230

It worked properly before this:

I've never seen it run on a Raspberry Pi

Information about my hardware and software:

• I am using this Linux distribution and version (often, shown by lsb_release -a):

No LSB modules are available.
Distributor ID:	Debian
Description:	Debian GNU/Linux 11 (bullseye)
Release:	11
Codename:	bullseye

• I am using this kernel version (shown by uname -a):

Linux linuxcnc 5.15.82-rt54-v8+ #1 SMP PREEMPT_RT Tue Dec 13 13:26:48 CET 2022 aarch64 GNU/Linux

• I am running ...
  • A binary version from linuxcnc.org (including buildbot.linuxcnc.org)
  • A binary I built myself
  • A binary version from some other source besides linuxcnc.org
• I am using this LinuxCNC version (shown in package manager or, for git versions, scripts/get-version-from-git):

alangibson@linuxcnc:~/build $ git branch
* 2.9
alangibson@linuxcnc:~/build $ git rev-parse HEAD
2c085f1d6f5ab90dd1829fb8f63be109f127b269

• I am using this user interface (GUI) (e.g., AXIS, Touchy, gmoccapy, etc): QtPlasmaC
• I am using this interface hardware vendor and chipset (e.g., parallel port, ethernet port, FPGA card): Mesa 7i96

[cradek]

Thanks for the detailed bug report! This may have been fixed by pull request #2302 which was merged into 2.9 and master since your version. Please update your 2.9 branch and retest.