Hello @julien-c ,
I am facing similar issues, attempting to upload a large file (just above 5GB) using git-lfs. I have a dual boot on my machine, and unfortunately did not manage to upload neither from Windows or Ubuntu 18.04.
I have git-lfs installed with the environment variable GIT_LFS_SKIP_SMUDGE=1 and ran
(transformers) λ transformers-cli lfs-enable-largefiles .
Local repo set up for largefiles

Interestingly, both the Windows and Ubuntu version return the following warning after adding the file:
E:\path\to\gpt-neo-1.3B (main -> origin)
(transformers) λ git add rust_model.ot
Encountered 1 file(s) that may not have been copied correctly on Windows:
        rust_model.ot

See: `git lfs help smudge` for more details.

Attempting to push returns a similar warning:
(transformers) λ git push
EOFoading LFS objects: 100% (1/1), 5.3 GB | 0 B/s
error: failed to push some refs to 'https://huggingface.co/EleutherAI/gpt-neo-1.3B'

I read that git-lfs has issues for files larger than 4GB on windows - but I am surprised to face issues on my Ubuntu partition. Am I missing something?