Cargo Features

[dependencies]
sawtooth-zmq = { version = "0.8.2-dev5", default-features = false, features = ["unstable", "zmq_has", "unstable-testing", "clippy"] }
default = zmq_has

The zmq_has feature is set by default whenever sawtooth-zmq is added without default-features = false somewhere in the dependency tree.

unstable unstable-testing?
zmq_has default

zmq_has was added in zeromq 4.1.

unstable-testing = compiletest_rs, unstable

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.

compiletest_rs unstable-testing?
clippy implicit feature

Enables clippy

clippy:

A bunch of helpful lints to avoid common pitfalls in Rust