Build error when packaging UE4.27 source built from https://github.com/Oculus-VR/UnrealEngine

Running into an error when packaging a project built using the UE4.27 fork downloaded from Github - OculusVR Unreal Engine on VS2022. Engine builds and runs fine but fails to package UATTempProj.proj. Thoughts on what might be going on? Specifically it seems to be angry about invalid numbers in FastJSON\Getters.cs.