Fails to pack/unpack

[vhbit]

Here is a test case:

#[test]
fn test_circular_str_vec() {
    let mut v: Vec<String> = Vec::new();
    v.push("VPRYWQT-JW47HTA-Y2ZTRGH-7MF2DGU-FY2X6E2-N3DKDRF-KCFBN4W-KOX4ZQ7".to_string());

    assert_msgpack_circular!(v);
}

I'm not sure what is so special about this string as initial test with "test" worked correctly.