From @keslerm on March 6, 2017 19:14

λ dotnet --version
1.0.0-rc4-004771

When using dotnet restore with either a nuget.config with multiple sources, or passing multiple -s options it only tries one source.

This means that when trying to do dotnet restore on a project that has a private repo and a public repo and pulls from both, the restore operation will fail because obviously some package disparity between the two repos will exist.

Results from running:
λ dotnet restore
Restoring packages for C:\Project\example.csproj...
Retrying 'FindPackagesByIdAsyncCore' for source 'https://privaterepo.com/FindPackagesById()?id='YamlDotNet.Signed''.
Response status code does not indicate success: 404 (Not Found).
Retrying 'FindPackagesByIdAsyncCore' for source 'https://privaterepo.com/FindPackagesById()?id='WebSocketSharp''.
Response status code does not indicate success: 404 (Not Found).
Retrying 'FindPackagesByIdAsyncCore' for source 'https://privaterepo.com/FindPackagesById()?id='EntityFramework.CodeFirstStoreFunctions''. `

Copied from original issue: microsoft/dotnet#361