const STABILISED_SPARSE_REGISTRY: &str = "This flag currently still sets the default protocol \
    to `sparse` when accessing crates.io. However, this will be removed in the future. \n\
    The stable equivalent is to set the config value `registries.crates-io.protocol = 'sparse'`\n\
    or environment variable `CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse`";