my less tired brain wonders about mixed clusters where (even if we move this to a module) the path may exist but the code may not be there. 

Before we make available the beams on nodes that don't have them we could check if `riak_core_ring_manager` is defined and running, but if we've already started migrating net_ticktime we're out of luck (unless we actually load the module on the node remotely?). If the first daemon process is always run on a real riak node perhaps we could use a capability to pre-empt this (there would still be a small window for error as caps converge on downgrade?).