Nuget restore for AzureDevOps failed to authenticate on CI machine

[greha]

Description

AzureDevOps nuget feeds aren't authenticated during CI build on our on premise build machines. Nuget alone however works with the credential providers and the env var: VSS_NUGET_EXTERNAL_FEED_ENDPOINTS

Expected behavior

Paket should be able to authenticate with AzureDevOps nuget feeds and restore packages.

Actual behavior

Paket fails to authenticate and restore nuget packages from AzureDevOps nuget feeds.

Known workarounds

Login on the buildmachine and do a manual paket restore, and wait for the UI authentication to pop up and login.

[forki]

Does #3765 (comment) help?

[greha]

Hi, yes this worked - thank you.

However during analyzing we discovered more strange behavior:

When we put the azd "netcore" and "netfx" credential providers to:

"C:\Users<User>\AppData\Local\NuGet\CredentialProviders"

We get this error although we made the changes suggested in your post and it is the public nuget feed:

10:10:35,070 WARN - Paket failed with 10:10:35,074 WARN - -> Could not download YamlDotNet 8.1. 10:10:35,075 WARN - -> Couldn't get package details for package YamlDotNet 8.1 on https://api.nuget.org/v3/index.json. 10:10:35,075 WARN - -> Could not retrieve data from 'https://nuget.org/api/v2/FindPackagesById()?semVerLevel=2.0.0&id='YamlDotNet'' 10:10:35,075 WARN - -> Credential provider returned an invalid result: [Information] [CredentialProvider]Username: 10:10:35,075 WARN - [Information] [CredentialProvider]Password: 10:10:35,075 WARN - Error: 10:10:35,075 WARN - -> JsonSerializationException: Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'Paket.CredentialProviderResultMessage' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly. 10:10:35,075 WARN - To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List<T> that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array. 10:10:35,075 WARN - Path '', line 1, position 1.

[ehhnwidex]

Hi, the proposed solutions does not seem to solve the problem at hand. As the purpose of the credential provider is to not having to store the credentials or apikey in a config file on the server.

However the problem seem to be that the Azure Artifacts Credential Provider from https://github.com/microsoft/artifacts-credprovider#environment-variables doesn't return a credential string in the required json format described at https://docs.microsoft.com/en-us/nuget/reference/extensibility/nuget-exe-credential-providers by default.

However if an aditional parameter OutputFormat (-F) with the value json, it returns a json object as expected.

As a work around i created a simple executable appending the -F parameter before the -Uri before calling %Userprofile%.nuget\plugins\netfx\CredentialProvider.Microsoft\CredentialProvider.Microsoft.exe, and placed it in %AppData%\Local\NuGet\CredentialProviders. This allows me to restore packages from our private NuGet feed using a credential provider with Paket.

It would be nice if we didn't have to use this workaround and paket could either append the -F flag it self if needed, or support the human readable format from Azure Artifacts Credential Provider like NuGet does.