Comment 27 for bug 43233

I just had this happening on an Ubuntu Edgy server running in a virtual machine, what a pain to get fixed. :) I finally found out that I had to open my virtual machine program, login to a seperate tty and sudo from there, as no ssh connection allowed me to do this.

It was the same as above, and neither sudo -v, sudo -K or sudo -k allowed me to enter a password.

This often happens just after reinstall of a system, too.