HandleFailure - TaskFailureDetails ErrorType returns (unknown)

[epDugas]

When the delegate that is assigned to RetryPolicy.HandleException executes, the TaskFailureDetails property: ErrorType is (unknown).
Because of this, IsCausedBy cannot resolve the Exception Type that caused the failure.
This only happens with Activity Functions. It does not happen with Sub-Orchestration Functions.

<PackageReference Include="Microsoft.Azure.Functions.Worker" Version="2.0.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.DurableTask" Version="1.2.2" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.2.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="2.0.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="2.0.0" />

[MarcFlynn2]

I face the same issue when running a durable function locally with the following project information

<TargetFramework>net8.0</TargetFramework>
<AzureFunctionsVersion>v4</AzureFunctionsVersion>

<PackageReference Include="Azure.Data.Tables" Version="12.10.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker" Version="2.0.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Timer" Version="4.3.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="2.0.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="2.0.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.ServiceBus" Version="5.22.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Storage" Version="6.6.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.DurableTask" Version="1.2.2" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.OpenApi" Version="1.5.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="2.0.0" />
<PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.22.0" />
<PackageReference Include="System.Linq.Async" Version="6.0.1" />

I raise the following exception in an Activity.

public class FatalException(Exception innerException) : Exception("Fatal Exception", innerException);

I create the TaskOptions as follow

	new TaskOptions(
		new RetryPolicy(
			maxNumberOfAttempts: activityRetrySettings.Value.MaxRetryNumber,
			firstRetryInterval: activityRetrySettings.Value.Interval,
			backoffCoefficient: activityRetrySettings.Value.BackoffCoefficient
		) {
			HandleFailure = IsRetryException
		});

And the hanldler is the following.

private static bool IsRetryException(TaskFailureDetails e)
{
	while (true)
	{
		if (e is null) return true;
		if (e.ErrorType == nameof(FatalException)) return false;
		e = e.InnerFailure;
	}
}

But the only ErrorType I get is "(unknown)".
Notice that the InnerFailure is also null, while I raised an exception with an inner exception.

[nytian]

Hey thanks for raising the issue. @epDugas @MarcFlynn2

This is a known issue and it's already been fixed starting from v1.3.0 Microsoft.Azure.Functions.Worker.Extensions.DurableTask . but please upgrade to our latest version.

Also, for .NET Isolated, use FailureDetails instead of InnerFailure or InnerException. By default, FailureDetails captures the error type, message, stack trace, and any nested inner exceptions (each stored as its own FailureDetails).

You should see more details here https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-error-handling?tabs=csharp-isolated#errors-in-activity-functions-and-sub-orchestrations