AsyncContext.Run(Func<Task>) retrying tasks that throw exceptions?

[stephendrew]

Hi Stephen,

Thanks for your great library!

I have a simple console app that uses AsyncContext.Run(Func) to run a task. If the task throws an exception, it seems to keep retrying the task over and over again....

Am I doing something stupid?

Cheers,
Steve

    class Program
    {
        static void Main(string[] args)
        {
            AsyncContext.Run(() => RunAsync());
        }

        static async Task RunAsync()
        {
            await DoSomethingAsync();

            throw new Exception();
        }

        static async Task DoSomethingAsync()
        {
            await Task.Delay(1000);
        }
    }

[StephenCleary]

I believe what you're seeing is actually due to the way the Visual Studio debugger acts with top-level exceptions. It is weird behavior (and quite possibly a bug), but if you run your app outside the debugger you'll see that it's not actually retrying the code. VS is just re-showing the exception for some unfathomable reason.

In particular, you'll see the same behavior with this code:

static void Main(string[] args)
{
    throw new Exception();
}