> Are these libraries just incompatible now?

Python says "Yes." Every environment manager I've seen, if your version ranges don't overlap for all your dependencies, will end up failing to populate the environment. Known issue; some people's big Python apps just break sometimes and then three or four open source projects have to talk to each other to un-fsck the world.

npm says "No" but in a hilarious way: if lib-a emits objects from lib-x, and lib-b emits objects from lib-x, you'll end up with objects that all your debugging tools will tell you should be the same type, and TypeScript will statically tell you are the same type, but don't `instanceof` the way you'd expect two objects that are the same type should. Conclusion: `instanceof` is sus in a large program; embrace the duck typing (and accept that maybe your a-originated lib-x objects can't be passed to b-functions without explosions because I bet b didn't embrace the duck-typing).