pub fn lint_feature_rules(&self, _config: &Config) -> Vec<Vec<String>> {
        let mut cases = Vec::new();

        if self == &Package::EspWifi {
            // Minimal set of features that when enabled _should_ still compile:
            cases.push(vec![
                "esp-hal/unstable".to_owned(),
                "builtin-scheduler".to_owned(),
            ]);
        }

        cases
    }
Additional feature rules to test subsets of features for a package.
xtask/src/lib.rs