We're attempting to upgrade our Ubuntu 12.04 system to 14.04. Our internet connection for the Linux server goes via a proxy server that requires authentication.
From a putty session I've been able to start Firefox to browse the web without being prompted for username/password details, by setting the http_proxy and http_proxys environment variables to include a valid username and password.
However, when I try to use the same setting in the
/etc/apt/apt.conf file, then I receive
407 Proxy Authentication Required errors when using either
do-release-upgrade -c or
I've read multiple discussions, but they all seem to point to this being the solution. Does anybody have any idea if there's maybe something else I've missed that needs to be set?