ValueError exception trying to expire backups

[dregad]

Hello,

I came upon this script, looking for a solution to cleanup old backups.

This maybe a silly newbie question, but at my first experimentation with a dry-run expire command (following indications in the README file), the program crashed with the following trace:

# tarsnapper --target "mantisbt_org_\$date" --deltas 1d 30d 360d - expire --dry-run 
1193 backups are matching
Traceback (most recent call last):
  File "/usr/local/bin/tarsnapper", line 8, in <module>
    sys.exit(run())
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/script.py", line 556, in run
    sys.exit(main(sys.argv[1:]) or 0)
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/script.py", line 546, in main
    command.run(job)
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/script.py", line 324, in run
    self.expire(job)
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/script.py", line 321, in expire
    self.backend.expire(job)
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/script.py", line 185, in expire
    to_keep = expire.expire(backups, job.deltas)
  File "/usr/local/lib/python3.8/dist-packages/tarsnapper/expire.py", line 50, in expire
    backups = sorted(backups.items(), key=lambda x: x[1], reverse=True)
ValueError: offset must be a timedelta strictly between -timedelta(hours=24) and timedelta(hours=24).

I'm not sure what to make of this error, or how to fix it. Thanks in advance for your help !

Please find attached the output of tarsnap --list-archives for reference
list-archives-20210529.txt