Troubleshooting

Before trying other solutions...

Please upgrade ocaml-jupyter kernel. Maybe a new version solves your problem.

$ opam update
$ opam upgrade jupyter
$ jupyter kernelspec install --name ocaml-jupyter "$(opam config var share)/jupyter"

Permission denied when jupyter kernelspec install

$ jupyter kernelspec install --name ocaml-jupyter "$(opam config var share)/jupyter"
[Errno 13] Permission denied: '/usr/local/share/jupyter'
Perhaps you want to install with `sudo` or `--user`?

jupyter kernelspec install tries to add a kernel to /usr/local/share/jupyter, but the directory cannot be accessed by a normal user. You have two solutions:

$ sudo jupyter kernelspec install --name ocaml-jupyter "$(opam config var share)/jupyter" # shared by all users
$ jupyter kernelspec install --user --name ocaml-jupyter "$(opam config var share)/jupyter" # available only to the current user

Permission denied: ~/.local or ~/.jupyter

Error like the following message when saving OCaml notebooks:

Unexpected error while saving file: Untitled.ipynb [Errno 13] Permission denied: '<YOUR_HOME_DIR>/.local/share/jupyter/notebook_secret'

In this case, Jupyter or the OCaml kernel cannot access ~/.local and/or ~/.jupyter because of different ownership or insufficient permission. You need to change the owner:

$ sudo chown -R YOUR_USERNAME ~/.local ~/.jupyter

or add permission:

$ sudo chmod -R 777 ~/.local ~/.jupyter