I work on the Protocol Buffers team at Google. I created upb (a small C protobuf implementation) and Bloaty (an ELF/Mach-O/PE/WASM binary size profiler).
Seattle, WA
Joined May 2011
Rust doesn't seem to have the concept of an internal/private crate. Any dependency of a public crate must also be publicly published on crates.io. There's no way to split a library into multiple crates in a way that is invisible to end users.

