A great related article is the introduction to PubGrub, the new solver algorithm for Dart's package manager. I especially liked the focus on better error messages, which can get pretty cryptic in other package managers.

https://medium.com/@nex3/pubgrub-2fb6470504f

The official docs are a rare learning resource, but require a bit more time to digest.

https://github.com/dart-lang/pub/blob/master/doc/solver.md