SubOrchestration with unserialized return type will cause function app to hang until timeout.

Description

I had a sub-orchestration that had a return type of a custom enum, defined in a namespace. When the orchestration reached the call for this sub-orchestration, the function will hang until it times out. I believe this behavior is caused if an unserializable type is used as a return value for the suborchestration call.

NOTE: JavaScript issues should be reported here: https://github.com/Azure/azure-functions-durable-js

Expected behavior

If an unsupported type is used in Suborchestration calls, it should be: Caught in analyzers. Throw an exception in runtime.

Actual behavior

Build completes without issues. Function app will hang until timeout.

Relevant source code snippets

[FunctionName("Orchestration_CreateICMSAndUpdateTriage")]
public static async Task<ICMCreation[]> CreateICMsAndUpdateTriage([OrchestrationTrigger] IDurableOrchestrationContext context, ILogger log)
{
      ...
   // Rerun Autopipe Processing.
   var dataFactoryPipeline = context.CallActivityAsync("Function_GetSetting", "DataFactory_DataFactoryName");
   DataFactoryStatus = await context.CallSubOrchestratorWithRetryAsync<DataFactoryStatus>("Orchestration_UpdateDataStores", Utilities.GetRetryOptions(), dataFactoryPipeline)

     ...

}

[FunctionName("Orchestration_UpdateDataStores")]
public static async Task<DataFactoryStatus> RunDataStorePipeline([OrchestrationTrigger] IDurableOrchestrationContext context, ILogger logger)
{
   var pipelinenName = context.GetInput<string>();
   string runId = await context.CallActivityWithRetryAsync<string>("Function_StartDataFactoryPipeline", Utilities.GetRetryOptions(), pipelinenName);
   DataFactoryStatus pipelineResult = await context.CallActivityWithRetryAsync<DataFactoryStatus>("Function_CheckAndWaitForPipelineRun", Utilities.GetRetryOptions(), runId);

   ...

   return pipelineResult;
}

Known workarounds

Changing the return type of RunDataStorePipeline from the enum DataFactoryStatus to a string fixed the issue.

App Details

Durable Functions extension version (e.g. v1.8.3): v2.9.0
Azure Functions runtime version (1.0 or 2.0): 4.16.4.20366
Programming language used: C#

Screenshots

This snapshot will show where "Function_GetSetting" was called and completed, but "Orchestration_UpdateDataStores" never starts until the timeout is reached 30 minutes later.

If deployed to Azure

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Timeframe issue observed: 2023-03-30T21:04:23Z > 2023-03-30T21:34:30Z
Function App name:
Function name(s): Orchestration_CreateICMSAndUpdateTriage, Orchestration_UpdateDataStores, Function_GetSetting,
Azure region: West US 3
Orchestration instance ID(s): 2851e4966a90451b9ae5d6d2f2a0d66c:2
Azure storage account name:

If you don't want to share your Function App or storage account name GitHub, please at least share the orchestration instance ID. Otherwise it's extremely difficult to look up information.

Azure / azure-functions-durable-extension