I had some issues with using sudo in a cron.
Basically I wanted to run a command as a specific user and I tested first, at the command line, su, which returned the error This account is not available. Using sudo, the command ran without errors.
However, when running from cron, the sudo command returned the following error: sudo: sorry, you must have a tty to run sudo.
I later found that using runuser and specifing a shell for the command to run, works.