Cargo Features

[dependencies]
polkadot-ckb-merkle-mountain-range = { version = "0.8.1", default-features = false, features = ["std"] }
default = std

The std feature is set by default whenever polkadot-ckb-merkle-mountain-range is added without default-features = false somewhere in the dependency tree.

std default

polkadot-ckb-merkle-mountain-range has 2 features without comments.