URGENT: AttributeError: module 'pygloo.rendezvous' has no attribute 'CustomStore'

When Running

collective.init_collective_group(
           world_size=train.world_size(), 
           rank=train.local_rank(), 
           backend="gloo"
		   )

I get

AttributeError: module 'pygloo.rendezvous' has no attribute 'CustomStore'

How could this be?