Renovate does not honor NuGet.config for dependencies found in .cake files

[shenke-adsk]

How are you running Renovate?

Self-hosted Renovate

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

GitHub Enterprise. Renovate version: 37.440.7

Please tell us more about your question or problem

I recently realized that when Renovate looks up packages used in .NET .cake files, it does not use the private registries defined in NuGet.config. It always only looks up in the public registry https://api.nuget.org/v3/index.json#protocolVersion=3.

Here is a test repository I created on github.com. I replaced the real company names and stuff to myawesomecompany. But this replicates the same issue I am experiencing on our hosted Renovate bot running on our internal GitHub Enterprise instance.

Here is the link to the job log. Clearly Renovate resolves packages in .csproj files file, but when it comes to packages referenced in .cake files, it does not look up in the private registry at all.

Logs (if relevant)

Logs

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