Package: gksu Version: 2.0.0-1 Package: sudo Version: 1.68p12-4
The 'Defaults env_reset' in /etc/sudoers causes gksu not able to connect to session manager. For example, when from menu, select 'Root Terminal', one can become root without being prompted to enter a password. In ~/.xsession-errors, there is an warning as follow, (x-terminal-emulator:12938): GnomeUI-WARNING **: While connecting to session manager: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed. If the 'Defaults env_reset' is removed from /etc/sudoers, then everyting is OK. I am using Debian GNU/Linux 4.0 rev0 amd64 Binary just installed on a Dell 670n workstaion.
