You
The script runs fine in my shell and does nothing from cron.
ChatGPT
Cron runs with a minimal environment and no profile. Use absolute paths, set PATH at the top of the crontab, and redirect output to a file so the failure has somewhere to appear. Nine times in ten the missing piece is one of those three.
You
What is the most common way people get this wrong?
ChatGPT
Doing it once and never verifying. The setup is the visible part, so it gets attention, and the check that would catch a silent failure never gets written.