Calling async ServerRpc that returns value crashes the server on 2021.2

[Jobus0]

Describe the bug
Simply calling an async UniTask ServerRpc from a client instantly crashes the server, whether it be in the editor or on a build, with Unity 2021.2. Also tested on 2021.1.13, but there was no issue there.

Repro project
Tiny project with a simple Player script that calls an async rpc to get randomized X position when spacebar is pressed.
Mirage Async RPC Test.zip

To Reproduce
Steps to reproduce the behavior:

1. Open the attached project.
2. Open the 'Scene' scene.
3. Build a player or duplicate the project so multiplayer can be tested.
4. Play game, host. Join with other client.
5. Press Spacebar key on the joined client to call the async rpc, instantly crashing the server process.

Desktop (please complete the following information):

• OS: Windows 10
• Build target: Editor/Windows
• Unity version: 2021.2.4
• Mirage version: v113.0.0

Additional context
The calling code looks like this:

public class Player : NetworkBehaviour
{
    private void Update()
    {
        if (IsLocalPlayer && Input.GetKeyUp(KeyCode.Space))
            StrafeByRandomValueFromServer().Forget();
    }

    private async UniTaskVoid StrafeByRandomValueFromServer()
    {
        float value = await RequestRandomValue();
        transform.position = new Vector3(value, 0f, 0f);
    }

    [ServerRpc]
    public UniTask<float> RequestRandomValue()
    {
        return UniTask.FromResult(Random.Range(-2, 2f));
    }
}

Crash log:
Player.log

[dragonslaya84]

We will try have look at this a resolve soon as possible. Thank you for the report and project to replicate it in.

[James-Frowen]

I can't seem to replicate the crash using the Player script.

I've also added extra tests to make sure it works for other return types.

[James-Frowen]

seems to be an issue that is effecting unity 2021.2.4

[Jobus0]

Yeah, 2021.1.x works fine. I haven't tested previous 2021.2.x versions, but 2021.2.5 is also broken.

[github-actions]

🎉 This issue has been resolved in version 113.0.3 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀