pub fn set_output_single_feature(&mut self, output_single_feature: bool) -> &mut Self {
        self.output_single_feature = output_single_feature;
        self
    }
Whether to unify feature sets for all dependencies.

By default, Hakari only produces output for dependencies that are built with more
than one feature set. If set to true, Hakari will produce outputs for all dependencies,
including those that don't need to be unified.

This is rarely needed in production, and is most useful for testing and debugging scenarios.
tools/hakari/src/hakari.rs