Cargo Features

[dependencies]
azure-iot-rs-sys = { version = "0.2.1", default-features = false, features = ["http", "amqp", "prov_client"] }
default = amqp, mqtt, prov_client

These default features are set whenever azure-iot-rs-sys is added without default-features = false somewhere in the dependency tree.

http prov_client
mqtt amqp default
prov_client default = http

azure-iot-rs-sys has 4 features without comments.