Function read_bundles 

pub fn read_bundles<'a>(
    command: &str,
    host: &dyn Host,
    dir: &str,
    cases: impl Iterator<Item = &'a DatasetCase>,
) -> Result<BTreeMap<String, BundleInput>, Done>

The bundles of cases from dir (spec 015, 3.3): absent files are left out for the library to judge (bundle-missing); a file that exists but cannot be read, is past the document limit or does not parse is supplied as that case’s load failure, and the command continues. Only an exhausted read budget stops it, because that depends on read order rather than on the bundle.