> Does Rust, like Go, have tools for freezing dependencies?

What tools are you referring to Go here? There are a handful of extra-standard mechanisms you can use to make it somewhat better (through clever hacks on urls and such), but the expectation in go-land seems to be that 'freezing your dependencies' is 'vendor them wholesale into your git repo', which is not exactly robust. Go's story on "application will always build" is kind of notoriously bad.