Unable to redirect to a GCP Artifact Registry Python repository with pip

[miguelnmiranda]

Related to #29

Description

When following redirects that don't point to one of the configured indexes pip will request credentials from the keyrings using the netloc taken from the target's location url (ref).

The present implementation relies on urlib.urlparse to determine hostname (which is part of netloc). urlparse requires urls to have a schema (or at least //) in order to detect a netloc (ref), which makes it misclassify a previously parsed netloc as a path (ref).

I proposed falling back to using the service as is when a hostname cannot be found (ex. when service is just a url's netloc).

Example

Using a private pypi server that redirects to a GCP Artifact Registry Python repository for certain dependencies.