Currently Kibana crashes with RangeError: Maximum call stack size exceeded when we have two NP plugins that have each other in requiredPlugins.

When such dependency is based on optionalPlugins error message is much better (still very vague though): Error: Topological ordering of plugins did not complete, these edges could not be ordered: [["plugin-a",{}],["plugin-b",{}]]

You can use licensing and security NP plugins to reproduce this.