Comment 14 for bug 1465086

The discussion on IRC is the following:

14:58 (sileht) oomichi, have you seen my comment that suggest to configure your .pip.conf
14:58 (sileht) I already use proxy everywhere and I just change this file and that works
14:59 (oomichi) sileht: yeah, I saw
14:59 (sileht) it's universall for all pip based python project
14:59 (oomichi) sileht: but http_proxy is more common on linux
15:00 (sileht) using passenv it is dangerous, a badly configured http_proxy can break unittest
15:00 (oomichi) sileht: what use case for bad configuration?
15:01 (oomichi) sileht: this is just for unit tests meaning development
15:01 (sileht) oomichi, some project setup http server and use request to connect to it
15:02 (sileht) oomichi, if http_proxy is set but not no_proxy with all hosts used in tests that will pass all requests to the proxy
15:03 (oomichi) sileht: yeah, that is very common thing on the combination of http_proxy and no_proxy
15:05 (oomichi) and if that is a problem, the other applications on the env also would be a problem
15:10 (sileht) Anyways if you use a proxy you should known how to configure app to use it, I have proposed solutions that doesn't risk to break tests and change code tree. That just my 2cents I'm not the only developer here.

I still am not sure what is the safe point of that even if blocking its usability.