Cargo Features

libmpv2-sys has no features set by default.

[dependencies]
libmpv2-sys = { version = "4.0.0", features = ["use-bindgen"] }
use-bindgen = bindgen

You can either use the pregenerated bindings, or gen new ones with bindgen

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.

bindgen build use-bindgen?