Improve error message reporting when running into a certificate issue

[kdheepak]

A colleague of mine ran into this issue when installing a package with uv.

And this was part of a larger install script to install a number of conda and python dependencies. And they concluded that this was an issue with the dependencies.

I made the same assumption as well, and since I had only ran this version on MacOS, I first thought "oh uv is resolving dependencies differently on macos and windows". And then when I tested it on my Windows VM, I didn't experience an issue which made me look at the error message more carefully.

Looking at the error message now, it is obvious it is a certificate issue. It says "Failed to download" and "UnknownIssuer". But it was easy to miss for two people (just two data points, I know)

I think the last line where "help: ..." is printed seems to imply it is because of a dependency version issue? And that might have been the source of confusion.

I'm wondering if there are incremental improvements possible here? Maybe uv can skip the help when running into a certificate issue? Or print a different help message that points the user to theuv docs on how to resolve SSL issues?

Feel free to close this issue if you think it's not worth any changes. After reading the uv docs and if I were to run uv sync from the command line myself, it would be super clear that this was a certificate issue to me. I'm coming at this from the perspective of making an automated install for a user that doesn't have to think about "conda" or "uv" or any of the dependencies involved to setup a project and would like the help messages to be more precise for a user that is using uv for the very first time.

[zanieb]

Thanks for the report!

@charliermarsh we may not want to show this message for download failures?

We should also probably special case the certificate errors.

[charliermarsh]

I think we now hint at using --native-tls at least?