Hi, I concur with others that it sounds like you simply don't have sudo installed.
As an aside, sudo-rs is packaged as of Debian 13 (trixie, currently testing) and I've been using it for a week now without complaints. sudo fans might like to give it a go. It replicates the functionality and configuration of sudo except for the parts it doesn't implement (on purpose). For my personal machines I didn't need to change anything about what I do. For some more complicated servers I had to change the sudoers configuration very slightly. Other sudo alternatives like doas, pleaser and even systemd's run0 are available, but they do of course work differently. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
