Cargo Features

flatpak-rs = { version = "0.18.1", default-features = false, features = ["derive", "extended_build_systems", "extended_mirror_urls_support"] }
default = extended_build_systems, extended_mirror_urls_support

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

derive = toml
extended_build_systems default
extended_mirror_urls_support default

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.

toml derive?

Enables toml ^0.5