Failure to load datasets in Owl: "input_value: unknown custom block identifier"

[gl-yziquel]

Hi.

I recently installed Owl and just now attempted to download the MNIST dataset to replicate the code at the following address:

https://github.com/owlbarn/owl/blob/main/examples/lazy_mnist.ml

After the Dataset.download_all () command has populated my ~/.owl/dataset folder, I get the following situation:

mini-me@virtucon ~> utop
Welcome to utop version 2.13.1 (using OCaml version 4.14.1)!
Type #utop_help for help about using utop.
─( 15:37:51 )─< command 0
utop # #require "owl";;
─( 15:37:51 )─< command 1
utop # open Owl;;
─( 15:37:57 )─< command 2
utop # Dataset.load_mnist_test_data ();;
2023-10-11 15:38:14.444 INFO : create /home/mini-me/.owl/dataset/ if not present
Exception: Failure "input_value: unknown custom block identifier".

[gl-yziquel]

Here is a stack trace:

mini-me@virtucon ~/h/s/mud-owl-net (master)> just run
_build/default/bin/main.exe
2023-10-11 17:58:48.952 INFO : create /home/mini-me/.owl/dataset/ if not present
Failure input_value: unknown custom block identifier
Raised by primitive operation at Stdlib__Marshal.from_bytes in file "marshal.ml", line 61, characters 9-35
Called from Stdlib__Fun.protect in file "fun.ml", line 33, characters 8-15
Re-raised at Stdlib__Fun.protect in file "fun.ml", line 38, characters 6-52
Called from Owl_dense_ndarray_generic.load in file "src/owl/dense/owl_dense_ndarray_generic.ml" (inlined), line 2070, characters 16-42
Called from Owl_dense_matrix_s.load in file "src/owl/dense/owl_dense_matrix_s.ml" (inlined), line 60, characters 13-29
Called from Owl_dataset.load_mnist_train_data in file "src/owl/misc/owl_dataset.ml", line 87, characters 4-54
Called from Owl_dataset.load_mnist_train_data_arr in file "src/owl/misc/owl_dataset.ml", line 110, characters 20-44
Called from Dune__exe__Main.main in file "bin/main.ml", line 19, characters 10-46
Called from Dune__exe__Main in file "bin/main.ml", line 28, characters 13-20
mini-me@virtucon ~/h/s/mud-owl-net (master)>