The engine we are using here (and when I have some free time I hope to OSS soon), allows you full control over dependencies and makes you resolve all conflicts. But it also gives you easy ways to do that. Upgrade to latest, Pick a specific version, Shade (w/rename) one of them along with whatever is using it to avoid the conflict, etc. And with API diffing you at least know if the upgrade or specific version options are API compatible for the actual use cases. @Czar