Today our more intrepid users sometimes form a cluster from unreleased versions in order to test out new functionality. This is usually fine, and indeed is encouraged, but can lead to difficulties if they happen to use two different builds of the same numbered version since there is no guarantee of compatibility between such builds. Clusters like this can behave quite strangely and it can be tricky to work out why. A similar issue occurs when using a remote cluster with an equal version but a different build hash.

I'm opening this issue to discuss whether we should prevent an invalid mix of nodes from forming a faulty cluster or remote cluster connection by sharing Build.CURRENT.hash() as well as Version.CURRENT somewhere in the handshaking process. If two nodes determine that they have the same numbered version, but a different build hash, then they would emit a warning and drop the connection.