If you make a tree of crate dependencies, the root is the standard library. So yes, you could build it all yourself with the standard library, it would just be

If you make a tree of crate dependencies, the root is the standard library. So yes, you could build it all yourself with the standard library, it would just be really unpleasant. I agree, it would be nice the if the rust foundation would give their blessing to some important crates like serde and regex, but putting them in the standard library only makes them harder to evolve. In particular, breaking changes go from being unpleasant to disallowed altogether.