Henk-Jaap Wagenaar

Results 1 issues of Henk-Jaap Wagenaar

This closes #6708 and is tangential to #4475. This makes Kerberos authentication available with a flag (`--enable-kerberos`). This is based on [another PR](https://github.com/pypa/pip/pull/4854), with the following high level difference: -...

needs rebase or merge