ERROR: No valid lockfile found when running --monitor in cronjob

[neilbags]

I''ve got a cronjob that looks like this:
@hourly /usr/sbin/sanoid --monitor-snapshots | grep -vE '^OK'
@hourly /usr/sbin/sanoid --monitor-health | grep -vE '^OK'

I'm occasionally seeing it error out:

Use of uninitialized value $checkmutex in scalar chomp at /usr/sbin/sanoid line 1488.
Use of uninitialized value $checkmutex in string eq at /usr/sbin/sanoid line 1490.
ERROR: No valid lockfile found - Did a rogue process or user update or delete it?

This is a laptop system that isn't always on. This seems to correspond to reboots or suspend maybe?. Maybe its clashing with the sanoid systemd timer? Or the two cron jobs are are trying to run simultaneously?

Is there a preferred way to do this that won't cause this error? Apologies if I've missed something obvious, I'm a brand new sanoid user (3 days) and loving the ergonomics of it so far. Well done devs!