Feed credentials in NuGet config not being used, causing Visual Studio prompt window

[ygeelen-tb]

We're running ProGet on IIS with no permissions for Anonymous users and have a NuGetDefaults.config file configured with packageSourceCredentials (https://docs.microsoft.com/en-us/nuget/consume-packages/configuring-nuget-behavior).
Yet we get a prompt for filling in credentials in Visual Studio all the time (both in Visual Studio 2015 and 2017) instead of reading them from the config file.
As I read in other support questions, the problem is that at first there's a GET request without credentials.

Do you have any real solution for this?
If not, perhaps a ProGet CredentialProvider exists somewhere?

Product: ProGet
Version: 4.7.6

[Guest]

This is a known issue with Visual studio; it occasionally does this.

Unfortunately, Visual Studio only supports VSO credential provider (it's hard coded to only accept that type). There is a GitHub issue somewhere to allow for a different credential provider, perhaps it's been changed in VS2017.

[ygeelen-tb]

We experience this issue very often..

I implemented a VS2017 credential provider that reads NuGetDefaults.config and passes the credentials. But it's always passing the same credentials as the first feed that is accessed (we have multiple feeds that require credentials).

So it seems that Visual Studio/default browser/CredentialProvider is caching the credentials for that domain.

[Guest]

Hmm, sounds like a NuGet/VS bug... definitely worth sharing this with them!