System.AggregateException: One or more errors occurred. (nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443)) (nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443)) (nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443)) (nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443)) (nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443)) ---> System.Net.Http.HttpRequestException: nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443) ---> System.Net.Sockets.SocketException (0xFFFDFFFF): nodename nor servname provided, or not known at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token) at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) --- End of inner exception stack trace --- at GitHub.Services.Common.VssHttpRetryMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at GitHub.Runner.Common.RedirectMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at GitHub.Runner.Common.ThrottlingReportHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken) at GitHub.Services.WebApi.VssHttpClientBase.SendAsync(HttpRequestMessage message, HttpCompletionOption completionOption, Object userState, CancellationToken cancellationToken) at GitHub.Services.WebApi.VssHttpClientBase.SendAsync(HttpMethod method, Guid locationId, Object routeValues, ApiResourceVersion version, HttpContent content, IEnumerable`1 queryParameters, Object userState, CancellationToken cancellationToken) at GitHub.DistributedTask.WebApi.TaskHttpClient.RaisePlanEventAsync[T](Guid scopeIdentifier, String planType, Guid planId, T eventData, CancellationToken cancellationToken, Object userState) at GitHub.Runner.Worker.JobRunner.CompleteJobAsync(IJobServer jobServer, IExecutionContext jobContext, AgentJobRequestMessage message, Nullable`1 taskResult) --- End of inner exception stack trace --- at GitHub.Runner.Worker.JobRunner.CompleteJobAsync(IJobServer jobServer, IExecutionContext jobContext, AgentJobRequestMessage message, Nullable`1 taskResult) at GitHub.Runner.Worker.JobRunner.CompleteJobAsync(IRunnerService server, IExecutionContext jobContext, AgentJobRequestMessage message, Nullable`1 taskResult) at GitHub.Runner.Worker.JobRunner.RunAsync(AgentJobRequestMessage message, CancellationToken jobRequestCancellationToken) at GitHub.Runner.Worker.JobRunner.RunAsync(AgentJobRequestMessage message, CancellationToken jobRequestCancellationToken) at GitHub.Runner.Worker.Worker.RunAsync(String pipeIn, String pipeOut) at GitHub.Runner.Worker.Program.MainAsync(IHostContext context, String[] args) ---> (Inner Exception #1) System.Net.Http.HttpRequestException: nodename nor servname provided, or not known (pipelinesghubeus2.actions.githubusercontent.com:443) ---> System.Net.Sockets.SocketException (0xFFFDFFFF): nodename nor servname provided, or not known at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.

The hosted runner: GitHub Actions 505 lost communication with the server. Anything in your workflow that terminates the runner process, starves it for CPU/Memory, or blocks its network access can cause this error.