I wrote a quick and dirty patch so that if the proxy is set up either in System/Preferences/Proxies or in the $http_proxy environment variable, it will be taken into account in ubiquity. This is thanks to the correction of bug #13661 where gksu has been given the ability to set $http_proxy according to System/Preferences/Proxies.
Besides, this proxy configuration is written in /etc/apt/apt.conf but this is not the best place because there is no graphical user interface to modify it. I think it will be best to remove the proxy configuration from this file as soon as the installation is finished. Finally, I noticed that the proxy configuration entered in System/Preferences/Proxies is not copied during the installation process: another bug to file. ** Attachment added: "http_proxy fix" http://librarian.launchpad.net/3391645/50mirror.ubuntu.patch -- behind proxy ubiquity won't work https://launchpad.net/bugs/42529 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs