If PHP ever segfaults, you need to grab a core dump to help investigate.
Just a braindump below of how to do it...
https://gist.github.com/mkubenka/cf977e9178a394850bd7b4d67efee3d0
sysctl kernel.core_pattern='| /usr/lib/systemd/systemd-coredump %p %u %g %s %t %c %e'
sysctl fs.suid_dumpable=2
sysctl kernel.core_uses_pid=0
Add to /etc/systemd/system.conf file:
DefaultLimitCORE=infinity
systemctl daemon-reload
Then to view:
coredumpctl list
coredumpctl info PID
coredumpctl gdb PID