Server extension could not be found


I have been trying to follow the instructions given at the link below to set up a server extension in local editable mode for JupyterLab.

The basic steps are:

cookiecutter (*has_server_extension* set to *y*)
pip install -e .
jupyter labextension develop . --overwrite
jupyter server extension enable jlab_ext_example

After the last step, I always get the following.

Enabling: jlab_ext_example
- Writing config: /usr/etc/jupyter
    - Validating jlab_ext_example...
      X Validation failed: The module 'jlab_ext_example' could not be found. Are you sure the extension is installed?

This is regardless of whether I use cookiecutter to create the project or just use the server-extension project from GitHub. Is this something to do with the build environment settings?


Could it be that you used a different name (other than jlab_ext_example) when filling in the cookiecutter template? Could you provide a list of files and directories that you have (e.g. via screenshot, or an ls command, or tree command)? Or ideally, do you have your example (in a state after running the cookiecutter) in a public repository, e.g. GitHub?