Attempt at shell.nix for jupytext

output

[nix-shell:~/notebook]$ jupyter lab
[W 19:16:02.862 LabApp] Error loading server extension jupytext
    Traceback (most recent call last):
      File "/nix/store/782wmrsfgkggsh5kbkfjlbmc2psq385h-python3.7-notebook-6.0.1/lib/python3.7/site-packages/notebook/notebookapp.py", line 1615, in init_server_extensions
        mod = importlib.import_module(modulename)
      File "/nix/store/gpnm7i19lpj8p43mjrdw03d0hjalmskl-python3-3.7.5/lib/python3.7/importlib/__init__.py", line 127, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
      File "<frozen importlib._bootstrap>", line 983, in _find_and_load
      File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
    ModuleNotFoundError: No module named 'jupytext'
[W 19:16:02.863 LabApp] JupyterLab server extension not enabled, manually loading...
[I 19:16:03.257 LabApp] JupyterLab extension loaded from /nix/store/i8792z8v30zmhfqz6s4rcw2drwzrcbry-python3.7-jupyterlab-1.2.2/lib/python3.7/site-packages/jupyterlab
[I 19:16:03.257 LabApp] JupyterLab application directory is /nix/store/2hy7c6k55a1dq2dmdw6g95by3i2n5c4i-jupyterlab-extended
[I 19:16:03.640 LabApp] Serving notebooks from local directory: /home/dylan/notebook
[I 19:16:03.641 LabApp] The Jupyter Notebook is running at:
[I 19:16:03.641 LabApp] http://localhost:8888/?token=78cc540b44191c11eb8ff4ec14fc2c2f8def1c8a3b28dd03
[I 19:16:03.641 LabApp]  or http://127.0.0.1:8888/?token=78cc540b44191c11eb8ff4ec14fc2c2f8def1c8a3b28dd03
[I 19:16:03.641 LabApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[W 19:16:03.649 LabApp] No web browser found: could not locate runnable browser.
[C 19:16:03.650 LabApp]

    To access the notebook, open this file in a browser:
        file:///home/dylan/.local/share/jupyter/runtime/nbserver-883-open.html
    Or copy and paste one of these URLs:
        http://localhost:8888/?token=78cc540b44191c11eb8ff4ec14fc2c2f8def1c8a3b28dd03
     or http://127.0.0.1:8888/?token=78cc540b44191c11eb8ff4ec14fc2c2f8def1c8a3b28dd03

shell.nix

let
  jupyter = import (builtins.fetchGit {
    url = https://github.com/tweag/jupyterWith;
    rev = "";
  }) {};

  iPython = jupyter.kernels.iPythonWith {
    name = "notebook";
    packages = p: with p; [
      numpy
      matplotlib
      jupytext
    ];
  };

  jupyterEnvironment =
    jupyter.jupyterlabWith {
      kernels = [ iPython ];
      directory = jupyter.mkDirectoryWith {
        extensions = [
          "jupyterlab_vim"
        ];
      };
      extraPackages = p: [p.python3Packages.jupytext];
    };
in
  jupyterEnvironment.env