Generating core files from systemd-coredumpctl

Arch Linux stores core dumps in the journal, so if you want to debug a core dump you first have to dump the core using systemd-coredumpctl
Examples (you may have to be root if not in the systemd-journal group):

List core dumps

~ $ systemd-coredumpctl

Dump to file named core based on pid

~ $ systemd-coredumpctl dump 6738 -o core

Dump to file named core based on executable name

~ $ systemd-coredumpctl dump a.out -o core