Cargo Features

IMDb has no features set by default.

[dependencies]
imdb = { version = "0.0.1", features = ["serde-impls"] }
serde-impls = serde, serde_derive

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.

serde serde-impls?
serde_derive serde-impls?