I've unfortunately hit a wall investigating this :( sudo should only override the prompt if passprompt_override is set in sudoers, or the env variable SUDO_PROMPT is set, and neither is set in bionic. Furthermore, it's not an issue with the binary, as I've tried taking the bionic sudo and putting it in a cosmic machine, and it works perfectly, honoring -p '' like the cosmic version does. That leaves the environment somehow, but I've run out of leads.
It does work properly in xenial and in cosmic, and the prompt seems to just be cosmetic anyway, so I'm marking this wontfix. ** Changed in: sudo (Ubuntu) Status: Confirmed => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1799857 Title: sudo -p '' displays a password prompt which it shouldn't To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/1799857/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs