Cargo Features

[dependencies]
spotify_dl_lib = { version = "0.3.21", default-features = false, features = ["mp3"] }
default = mp3

The mp3 feature is set by default whenever spotify_dl_lib is added without default-features = false somewhere in the dependency tree.

mp3 default

Enables mp3lame-encoder ^0.1.5

spotify_dl_lib has 2 features without comments.