Extension method to add "logical" stack trace to async methods, with usage example. Copy/paste in Linqpad and add the following namespaces: - System.Runtime.CompilerServices - System.Threading.Tasks

AsyncStackTrace.cs

async void Main()
{
    try
    {
        await FooAsync().AsyncTrace();
    }
    catch(Exception ex)
    {
        ex.FullTrace().Dump();
    }
}

async Task FooAsync()
{
    await Console.Out.WriteLineAsync("Entering FooAsync");
    await BarAsync().AsyncTrace();
    await Console.Out.WriteLineAsync("Leaving FooAsync");
}

async Task BarAsync()
{
    await Console.Out.WriteLineAsync("Entering BarAsync");
    string s = await BazAsync().AsyncTrace();
    Console.WriteLine(s);
    await Console.Out.WriteLineAsync("Leaving BarAsync");
}


async Task<string> BazAsync()
{
    await Console.Out.WriteLineAsync("Entering BazAsync");
    throw new Exception("Oops");
    return "hello world";
    await Console.Out.WriteLineAsync("Leaving BazAsync");
}


static class AsyncExceptionExtensions
{
    public static async Task AsyncTrace(
        this Task task,
        [CallerMemberName] string callerMemberName = null,
        [CallerFilePath] string callerFilePath = null,
        [CallerLineNumber] int callerLineNumber = 0)
    {
        try
        {          
            await task;
        }
        catch (Exception ex)
        {
            AddAsyncStackTrace(ex, callerMemberName, callerFilePath, callerLineNumber);
            throw;
        }
    }
    
    public static async Task<T> AsyncTrace<T>(
        this Task<T> task,
        [CallerMemberName] string callerMemberName = null,
        [CallerFilePath] string callerFilePath = null,
        [CallerLineNumber] int callerLineNumber = 0)
    {
        try
        {	        
            return await task;
        }
        catch (Exception ex)
        {
            AddAsyncStackTrace(ex, callerMemberName, callerFilePath, callerLineNumber);
            throw;
        }
    }
    
    private static void AddAsyncStackTrace(Exception ex, string callerMemberName, string callerFilePath, int callerLineNumber = 0)
    {
        var trace = ex.Data["_AsyncStackTrace"] as IList<string>;
        if (trace == null)
            trace = new List<string>();
        trace.Add(string.Format("@{0}, in '{1}', line {2}", callerMemberName, callerFilePath, callerLineNumber));
        ex.Data["_AsyncStackTrace"] = trace;
    }
    
    public static string AsyncTrace(this Exception ex)
    {
        var trace = ex.Data["_AsyncStackTrace"] as IList<string>;
        if (trace == null)
            return string.Empty;
        return string.Join("\n", trace);
    }
    
    public static string FullTrace(this Exception ex)
    {
        var trace = ex.Data["_AsyncStackTrace"] as IList<string>;
        if (trace == null)
            return string.Empty;
        return string.Format("{0}\n--- Async stack trace:\n\t", ex)
             + string.Join("\n\t", trace);
    }
}