I'm also have problem with proxy, becouse I have separate proxy for internet connection and for apt (accepts only package downloading), but init_proxy() in utils.py prefer Acquire::http::Proxy then env settings. So I can't connect to http://changelogs.ubuntu.com from second proxy.
Solution for me was temporary set apt proxy the same as internet proxy.
I'm also have problem with proxy, becouse I have separate proxy for internet connection and for apt (accepts only package downloading), but init_proxy() in utils.py prefer Acquire: :http:: Proxy then env settings. So I can't connect to http:// changelogs. ubuntu. com from second proxy.
Solution for me was temporary set apt proxy the same as internet proxy.