uv pip install not respecting index.authenticate on followup requests #13737
Description
Summary
PR #12470 updated the pip commands to respect the index.authenticate settings, however, this seems to only apply to the initial request. Once the package is found the subsequent request to download the package is first made unauthenticated. I can verify this both in the uv logs and by looking at the logs of our Python index. Due to the specifics of our index setup, this causes the download to fail.
UV logs
Initial good request:
DEBUG No cache entry for: https://<REPO_URL>/root/pypi/+simple/<PACKAGE>/
TRACE Sending fresh GET request for https://<REPO_URL>/root/pypi/+simple/<PACKAGE>/
TRACE Handling request for https://<REPO_URL>/root/pypi/+simple/<PACKAGE>/ with authentication policy always
Followup bad request:
DEBUG No cache entry for: https://<REPO_URL>/root/pypi/+<HASH>/<PACKAGE>-py3-none-any.whl
TRACE Sending fresh HEAD request for https://<REPO_URL>/root/pypi/+<HASH>/<PACKAGE>-py3-none-any.whl
TRACE Handling request for https://<REPO_URL>/root/pypi/+<HASH>/<PACKAGE>-py3-none-any.whl with authentication policy auto
Platform
Fedora Linux 6.14.6-300.fc42.x86_64 x86_64 GNU/Linux
Version
uv 0.7.8
Python version
Python 3.13.3