Cargo Features

[dependencies]
multiboot2-common = { version = "0.2.1", default-features = false, features = ["alloc", "builder", "unstable"] }
default = builder

The builder feature is set by default whenever multiboot2-common is added without default-features = false somewhere in the dependency tree.

alloc builder
builder default = alloc
unstable

multiboot2-common has 4 features without comments.