Cargo Features

protobuf2 has no features set by default.

protobuf2 = { version = "4.0.0-alpha.2", features = ["with-bytes"] }
with-bytes = bytes

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

bytes with-bytes?

Affects message::Message.parse_from_tokio_bytes, runtime_types::RuntimeTypeTokioBytes, runtime_types::RuntimeTypeTokioChars, types::ProtobufTypeTokioBytes, types::ProtobufTypeTokioChars