I'm also running into situations where I have been required to delete the "Acquire proxy line" from a machine's apt.conf even if it is another physical machine (i.e. not localhost, not a VM on the Apt Proxy machine).
-- apt-proxy crashes when accessed from localhost https://launchpad.net/bugs/66042 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
