Current Status of Cargo + Authentication

Is there a way to coerce cargo build to use ~/.cargo/credentials.toml tokens when it downloads crates? Or, some way of getting git-fetch-with-cli, or ssh, to work for crate download as well as for the index?

I have it working to logon, publish, yank, and if I were to disable anonymous index I can get git to read with creds, It's only the download that seems to be being resistant.

I've read all the docs, and have been picking through the source, and it seems that one should be able to use some kind of credential to download a crate from a private repo, but I haven't been able to find the right combination of magic.