Windows Standalone Build fails

U2019.2.0.b6

ArgumentException: The Assembly nunit.framework is referenced by Unity.PerformanceTesting ('Library/ScriptAssemblies/Unity.PerformanceTesting.dll'). But the dll is not allowed to be included or could not be found.
UnityEditor.AssemblyHelper.AddReferencedAssembliesRecurse (System.String assemblyPath, System.Collections.Generic.List`1[T] alreadyFoundAssemblies, System.String[] allAssemblyPaths, System.String[] foldersToSearch, System.Collections.Generic.Dictionary`2[TKey,TValue] cache, UnityEditor.BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:154)
UnityEditor.AssemblyHelper.FindAssembliesReferencedBy (System.String[] paths, System.String[] foldersToSearch, UnityEditor.BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:194)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Any thoughts?

Seems to be fixed in U2019.2.0b7