Function enumerate_pack_objects 

pub fn enumerate_pack_objects(
    odb: &Odb,
    wants: &[ObjectId],
    haves: &[ObjectId],
    opts: &PackEnumerateOptions<'_>,
) -> Result<PackObjectSelection>

Select pack objects using bitmap reachability when possible, otherwise the object walk.

Errors

Propagates repository read failures. Missing want objects error; missing have objects are skipped.