> I can't tell how to label this bug report because I don't know where pip comes from: as far as I knew this is a bug in something called urllib3, which seemed to me that was related to Python itself, or maybe in the way pip is calling it, and I assumed pip was part of the Python project too.

What you’re seeing in your stack trace is an issue with packages developed independently of the Python standard library. pip (https://github.com/pypa/pip), requests (https://github.com/kennethreitz/requests) and urllib3 (https://github.com/shazow/urllib3) are all maintained externally and hosted on PyPI (https://pypi.python.org/pypi). Issues here are for bugs, enhancements and such for the Python standard library. Each one of the aforementioned projects (with the caveat of pip in Python 3.4+) maintain their own sets of issues on Github.

> Thank you for mentioning issue 23328, which did not come up in a search I did previous to filing my report: it does seem quite related.
> And that issue is marked as "Library (Lib)" and nobody complained about it so maybe this issue should be marked like that too.

Indeed it does seem related and it’s possible that urllib3 took parts of the code from urllib, which /is/ part of the standard library and is what 23328 was reported against, hence the “Lib” tag for that one.

> Please somebody who knows what's the best way to move this forward relabel it as necessary.

I’ll add a few people who may be interested in this issue, but I imagine that the issue would likely be moved to the urllib3 project.

Hope that all makes sense.