Rust-gdb no prettify variables properly

Hello folks, I'm reading Debugging Rust apps with GDB. But when I going to (gdb) p *animals statement, the result are not the same.

Result in the article:

(gdb) p *animals
$2 = Vec(size=3) = {rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Cat, name: "Chip", age: 4}, rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Cat, name: "Nacho", age: 6}, rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Dog, name: "Taco", age: 2}}

here is mine (debian bullseye, gdb version: Debian 10.1-1.7):

(gdb) p *animals
$2 = Vec(size=3) = {
  rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Cat, name: alloc::string::String {vec: alloc::vec::Vec<u8> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: 0x5555555a3ad0, _marker: core::marker::PhantomData<u8>}, cap: 4, alloc: alloc::alloc::Global}, len: 4}}, age: 4}, 
  rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Cat, name: alloc::string::String {vec: alloc::vec::Vec<u8> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: 0x5555555a3af0, _marker: core::marker::PhantomData<u8>}, cap: 5, alloc: alloc::alloc::Global}, len: 5}}, age: 6}, 
  rust_gdb_example::Animal {kind: rust_gdb_example::AnimalType::Dog, name: alloc::string::String {vec: alloc::vec::Vec<u8> {buf: alloc::raw_vec::RawVec<u8, alloc::alloc::Global> {ptr: core::ptr::unique::Unique<u8> {pointer: 0x5555555a3b10, _marker: core::marker::PhantomData<u8>}, cap: 4, alloc: alloc::alloc::Global}, len: 4}}, age: 2}}

Look like name field not decode correctly.

I also try to use gdb 8.3 (compile by myself), but still not the same:

# start gdb by following command ...
RUST_GDB=/tmp/gdb-8.3/gdb/gdb rust-gdb ~/test/rust-gdb-example/target/debug/examples/basic

...

(gdb) p *animals
$2 = alloc::vec::Vec<rust_gdb_example::Animal> {buf: alloc::raw_vec::RawVec<rust_gdb_example::Animal, alloc::alloc::Global> {ptr: core::ptr::unique::Unique<rust_gdb_example::Animal> {pointer: 0x5555555a3480, _marker: core::marker::PhantomData<rust_gdb_example::Animal>}, cap: 3, alloc: alloc::alloc::Global}, len: 3}

This is the first time I'm playing with gdb. Any suggestions are very welcome. Thanks.