Invalid code generation with more than one Entity GhostField in 1.9.1

Multiplayer & Networking Netcode for Entities
, ,
1

I have an component with 2 ghost entities, taken directly out of the character controller example. The class looks like this:

[GhostComponent]
public struct ThirdPersonPlayer : IComponentData
{
    [GhostField]
    public Entity ControlledCharacter;
    [GhostField]
    public Entity ControlledCamera;
}

Netcode for entities generates the following code:

static void CopyToSnapshotGenerated(in GhostSerializerState serializerState, ref Snapshot snapshot, ref ThirdPersonPlayer component)
        {
                snapshot.ControlledCharacter = 0;
                snapshot.ControlledCharacterSpawnTick = Unity.NetCode.NetworkTick.Invalid.SerializedData;
                if (serializerState.GhostFromEntity.TryGetComponent(component.ControlledCharacter, out var ghostComponent))
                {
                    snapshot.ControlledCharacter = ghostComponent.ghostId;
                    snapshot.ControlledCharacterSpawnTick = ghostComponent.spawnTick.SerializedData;
                }
                snapshot.ControlledCamera = 0;
                snapshot.ControlledCameraSpawnTick = Unity.NetCode.NetworkTick.Invalid.SerializedData;
                if (serializerState.GhostFromEntity.TryGetComponent(component.ControlledCamera, out var ghostComponent))
                {
                    snapshot.ControlledCamera = ghostComponent.ghostId;
                    snapshot.ControlledCameraSpawnTick = ghostComponent.spawnTick.SerializedData;
                }
        }

Note the 2 out var ghostComponent at the same scope. They produce the following error in the console:

Temp/NetCodeGenerated/Assembly-CSharp/2062241058503599662_ThirdPersonPlayerSerializer.cs(65,105): error CS0128: A local variable or function named 'ghostComponent' is already defined in this scope

This seems similar to an old bug:

I opened bug report case 123079 for this.

2

Similar to mine as well.

3

My reported case has just been put under review :grin:. I’ve added your GhostComponent code snippet and case number to my report, as it appears to be the same bug manifesting in different locations causing the same issue.

4

ty @CyborgRaven
My bug report also moved to in review. It definitely looks like a duplicate.

As a workaround I downgraded to 1.9.0, just update the manifest.json

5

Yeah, that can temporarily work around the issue, but upgrading the project to a higher Unity version will still fail due to the compile error.

Also, it seems the issue was already created (MTTB-1720) before I added your code snippet to my report (even before my report was put under review), so your code isn’t mentioned in the issue.

6

Just to clarify, the original ticket got stucked in the pipeline so the team didn’t get it before, after your thread @CyborgRaven I created ticket for us (as a measure before we will get the original ticket) + pinged around

I updated the description to include also your case @goldbug and we will prioritize fixing this this week

7

This has been fixed in the recently released 1.9.3 patch.