artifacts-credprovider: 'dotnet restore' unhandled exception with NuGetCredentialProvider

Hey team,

I’m not sure if this is an issue with the dotnet CLI or with the credential provider. I’ll try this repository first. I’ve also reviewed the other open issues and it this doesn’t appear to be related.

We are using Azure Artifacts and restoring packages in a docker container:

WORKDIR /nuget_cache_warmer
COPY **/*.csproj ./
RUN for f in ./*.csproj; do dotnet restore $f --source $NUGET_SOURCE --source https://api.nuget.org/v3/index.jsonl; done

This is our base image: FROM microsoft/dotnet:2.1-sdk

Intermittently, I start to see:

Unhandled Exception:  [0m [91mSystem.Threading.Tasks.TaskCanceledException: A task was canceled.
NuGet.Protocol.Plugins.MessageDispatcher.DispatchWithNewContextAsync[TOutgoing,TIncoming](IConnection connection, MessageType type, MessageMethod method, TOutgoing payload, CancellationToken cancellationToken) at NuGet.Protocol.Plugins.SymmetricHandshake.HandshakeAsync(CancellationToken cancellationToken) at NuGet.Protocol.Plugins.Connection.ConnectAsync(CancellationToken cancellationToken)
at NuGet.Protocol.Plugins.PluginFactory.CreateFromCurrentProcessAsync(IRequestHandlers requestHandlers, ConnectionOptions options, CancellationToken sessionCancellationToken)
at NuGetCredentialProvider.Program.Main(String[] args)
at NuGetCredentialProvider.Program.<Main>(String[] args)

This happens more than once during the restore processing, but not for every .csproj file.

What is interesting compared to other issues is the restore process will complete, and I can run the next docker step to build my project successfully.

If it matters, the docker build is running on a Linux TeamCity agent. If I run dotnet restore --disable-parallel, the exception does not occur, however the restore takes twice as long (as expected).

Since I can still restore successfully this isn’t a huge problem, though I thought I’d report it.