Cargo Features

better-blockmap has no features set by default.

[dependencies]
better-blockmap = { version = "2.0.1", features = ["window_size"] }
window_size = rug

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.

rug window_size?