You can use the `cargo graph` [0] command to get a graphviz view of the dependency graph. The `Cargo.lock` file which Cargo generates should also contain all the information you want in machine-readable form.

[0]: https://github.com/kbknapp/cargo-graph

No, but that would be a good project. Probably the easiest way at the moment is to see the compilation output. E.g. from the CI logs:

https://travis-ci.org/SergioBenitez/Rocket/jobs/465537062