patrick@wkdev:~/checkout/WebKit$ rr record echo 'hello world'
rr needs /proc/sys/kernel/perf_event_paranoid <= 1, but it is 2.
Change it to 1, or use 'rr record -n' (slow).
Consider putting 'kernel.perf_event_paranoid = 1' in /etc/sysctl.d/10-rr.conf.
See 'man 8 sysctl', 'man 5 sysctl.d' (systemd systems)
and 'man 5 sysctl.conf' (non-systemd systems) for more details.