 := setupCacheManager(t, tmpdir, "native", snapshotter)  defer cm.Close()   ch := []string{   "ADD foo file data0",   "ADD bar file data0",   "ADD d0 dir",   "ADD d0/abc file data0",   "ADD d0/def symlink abc",   "ADD d0/ghi symlink nosuchfile",  }   ref := createRef(t, cm, ch)  