uv publish does not recognize UV_INDEX_{name}_PASSWORD and UV_INDEX_{name}_USERNAME

[SalttownUser]

I have an issue using the uv publish command. I'm trying to upload a package to a private GitLab package registry and getting check error.

The index url is a GitLab group url combining packages inherited from multiple projects in the group:

[[tool.uv.index]]
name = "gitlab-private"
url = "https://example.org/api/v4/groups/1/packages/pypi/simple"
default = true
publish-url = "https://example.org/api/v4/projects/2/packages/pypi"

I did use these environment variable with credentials for url:

UV_INDEX_GITLAB_PRIVATE_PASSWORD
UV_INDEX_GITLAB_PRIVATE_USERNAME

and

UV_PUBLISH_USERNAME
UV_PUBLISH_PASSWORD

containing the credentials to push packages to publish-url.

uv publish --index gitlab-private -v
DEBUG uv 0.5.11 (c4d0caaee 2024-12-19)
warning: `uv publish` is experimental and may change without warning
DEBUG Publishing with index gitlab-private
DEBUG Not a distribution filename: `.gitignore`
Publishing 6 files https://example.org/api/v4/projects/2/packages/pypi
DEBUG Using request timeout of 900s
DEBUG Checking for my_package-py3-none-any.whl in the registry
DEBUG No cache entry for: https://example.org/api/v4/projects/2/packages/pypi/simple/my_package/
DEBUG No netrc file found
error: Failed to query check URL
  Caused by: Package `my_package` was not found in the registry

When I add the credentials for index to the url with url = "https://user:[email protected]/api/v4/groups/1/packages/pypi/simple" everything works.

Expected behavior

uv publish should use UV_INDEX_{name}PASSWORD and UV_INDEX{name}_USERNAME to
authenticate with the index "name" to check the package dependencies.

Originally posted by @SalttownUser in #9775

[charliermarsh]

I believe this is the same as #9845?