Found a work around here: http://www.ubuntuforums.org/showpost.php?p=1104006&postcount=3
Delete the line Acquire::http::Proxy "false"; from apt.conf. For whatever reason, apt-proxy now works just fine from localhost, as well as the second scenario in which it's a different VM on the same 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