I have experience a similar problem, by mistake I removed the hostname of my machine and it was automatically set to 'none', I re-started my computer and then I could not perform any task using sudo cause all the time I received the error: sudo: unable to lookup (none) via gethostbyname()
I had to re-start in rescue mode and add manually as root the correct hostname in the /etc/hostname and /etc/hosts files Why does sudo need to perform a 'gethostbyname()'? -- sudo shouldn’t ABSOLUTELY NEED to look up the host it’s running on https://launchpad.net/bugs/32906 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
