Not to mention that when user does not set proxy for apt (in /etc/apt/apt.conf.d), then neither "sudo apt-get ..." nor "sudo aptitude ... " nor update-manager at large work. And my guess is that whatever is the GUI tool provided in Ubuntu to set proxy, it does not configure apt proxy.
One has to resort to sudo -i followed by the command. Then proxy is set.
Solving this ticket should also solve these issues.
Not to mention that when user does not set proxy for apt (in /etc/apt/ apt.conf. d), then neither "sudo apt-get ..." nor "sudo aptitude ... " nor update-manager at large work. And my guess is that whatever is the GUI tool provided in Ubuntu to set proxy, it does not configure apt proxy.
One has to resort to sudo -i followed by the command. Then proxy is set.
Solving this ticket should also solve these issues.