Why does the compiler not know that I'm passing a Func<Task> to Match?

[MrYossu]

Probably doing something stupid here, but after a very helpful discussion about a similar question, I thought I had the hang of async lambdas. However, I've got another warning, and I don't understand why.

I have a two methods (implementation omitted for clarity)...

TryAsync<string> Jim()
async Task DoStuff(string str)

I'm using them like this...

await Jim()
  .Match(async str => await DoStuff(str), ex => LogError(ex));

Now, based on the explanation I had before, I would have expected that as DoStuff is an async method, the compiler would use the Func<string, Task> overload of Match, and so be happy with the fact that the lambda I'm passing for the happy path is async.

However, hovering my mouse over Match shows that it's using the overload that takes an Action<string>, and Resharper gives me a warning "Avoid using 'async' lambdas when delegate return type is void."

Can anyone explain why this is happening? What should I have done to make sure the right overload is called?

Thanks

[MrYossu]

Predictably, right after posting my question, I managed to sort it out! However, I'm going to leave the question here, as I still don't really understand it.

I sorted out the warning by changing the code to this...

await Jim()
  .Match(async str => await DoStuff(str), ex => Task.Run(() => LogError(ex)));

Now that both lambdas are async, the right overload is called.

What I don't understand is why the compiler didn't use the Func<string, Task> overload before. The warning was on the first lambda, which was async.

Anyone able to explain? Thanks.