le(t *testing.T) {  t.Parallel()  tmpdir, err := ioutil.TempDir("", "buildkit-state")  require.NoError(t, err)  defer os.RemoveAll(tmpdir)   snapshotter, err := native.NewSnapshotter(filepath.Join(tmpdir, "snapshots"))  require.NoError(t, err)  cm, _ := 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)   // for the digest values, the actual values are not important in development  // phase but consistency is   cc, err := newCacheContext(ref.Metadata(), nil)  require.NoError(t, err)   _, err = cc.Checksum(context.TODO(), ref, "