Cargo Features

perspective-client has no features set by default.

[dependencies]
perspective-client = { version = "3.0.3", features = ["external-proto", "external-protoc"] }
external-proto = protobuf-src
external-protoc

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.

protobuf-src build external-proto?