Originally reported by: wichert (Bitbucket: wichert, GitHub: wichert)

There are valid reasons for customising how URLs are loaded. For example lovely.buildouthttp does this to support authentication for private servers. zc.buildoutsftp has a similar need.

Since setuptools does not expose an API for this those tools try to do this by replacing the URL opener setuptools uses, but this is fragile and causes breakage when setuptools internals change. Ticket #61 is an example of this. It would be useful if setuptools had an API that makes it possible to hook into the URL downloading process to make this more flexible.

• Bitbucket: https://bitbucket.org/pypa/setuptools/issue/149