NullReferenceException running ProBuilder API from a build

I can use the ProBuilder 4.2.3 API from the editor just fine but any build I create on macOS using Unity 2018.4 throws null refs when I try to extrude a face. Here is the script that will recreate the issue. Attach it to the default ProBuilder cube. Note that I also tried using the current preview source from GitHub, same problem.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.ProBuilder;
5. using UnityEngine.ProBuilder.MeshOperations;
6.  
7. public class ExtrudeCubeAtStart : MonoBehaviour {
8.  
9.     public ProBuilderMesh ProBuilderMesh {
10.         get {
11.             if (proBuilderMesh == null) {
12.                 proBuilderMesh = gameObject.GetComponent<ProBuilderMesh>();
13.                 if (proBuilderMesh == null) {
14.                     Debug.LogError("ProBuilderMeshOperations.ProBuilderMesh.getter FAILED to get ProBuilderMesh");
15.                 }
16.             }
17.             return proBuilderMesh;
18.         }
19.     }
20.  
21.     private ProBuilderMesh proBuilderMesh = null;
22.  
23.     public void Start() {
24.         Debug.Log("ExtrudeCubeAtStart.Start()");
25.  
26.         int indexFace = 2;
27.         Face[] faces = new Face[1];
28.         faces[0] = ProBuilderMesh.faces[indexFace];
29.         ProBuilderMesh.Extrude(faces, ExtrudeMethod.FaceNormal, distance : 0.5f);
30.         ProBuilderMesh.ToMesh();
31.         ProBuilderMesh.Refresh();
32.     }
33. }

Here is the stack trace:

NullReferenceException: Object reference not set to an instance of an object

  at UnityEngine.ProBuilder.SharedVertex.GetSharedVertexLookup (System.Collections.Generic.IList`1[T] sharedVertices, System.Collections.Generic.Dictionary`2[TKey,TValue] lookup) [0x00001] in /Users/robert/workspace/unity/examples/Unity.2018.4/Library/PackageCache/com.unity.probuilder@4.2.3/Runtime/Core/SharedVertex.cs:144 

  at UnityEngine.ProBuilder.ProBuilderMesh.get_sharedTextureLookup () [0x00022] in /Users/robert/workspace/unity/examples/Unity.2018.4/Library/PackageCache/com.unity.probuilder@4.2.3/Runtime/Core/ProBuilderMesh.cs:341 

  at UnityEngine.ProBuilder.MeshOperations.ExtrudeElements.ExtrudeAsGroups (UnityEngine.ProBuilder.ProBuilderMesh mesh, System.Collections.Generic.IEnumerable`1[T] faces, System.Boolean compensateAngleVertexDistance, System.Single distance) [0x0003d] in /Users/robert/workspace/unity/examples/Unity.2018.4/Library/PackageCache/com.unity.probuilder@4.2.3/Runtime/MeshOperations/ExtrudeElements.cs:372 

  at UnityEngine.ProBuilder.MeshOperations.ExtrudeElements.Extrude (UnityEngine.ProBuilder.ProBuilderMesh mesh, System.Collections.Generic.IEnumerable`1[T] faces, UnityEngine.ProBuilder.ExtrudeMethod method, System.Single distance) [0x00013] in /Users/robert/workspace/unity/examples/Unity.2018.4/Library/PackageCache/com.unity.probuilder@4.2.3/Runtime/MeshOperations/ExtrudeElements.cs:30 

  at ExtrudeCubeAtStart.Start () [0x00029] in /Users/robert/workspace/unity/examples/Unity.2018.4/Assets/ExtrudeCubeAtStart.cs:29 

 

Did you test the code by doing a build and running stand-alone? Preview.4 does not work for me on Unity.2018.4 LTS. If you run it in development mode you can see the errors in-game.

Also, even though I pulled down preview.4 via the package manager, I have to manually edit the cached packages to fix the missing HDR pipeline requirement fatal error.