Error when running installation steps on macOS

[JasonWeill]

Description

The README file recommends building the code as follows:

# Clone the repo to your local environment
# Change directory to the jlab_enhanced_cell_toolbar [sic] directory
# Install package in development mode
pip install -e .
# Link your development version of the extension with JupyterLab
jupyter labextension develop . --overwrite
# Rebuild extension Typescript source after making changes
jlpm run build

I get an error when running the second command above on macOS 11.6.2 (Big Sur) with conda 4.11.0 and Python 3.9.7.

Reproduce

1. Run pip3 install -e . (Not pip, which runs Python 2 by default on macOS Big Sur). Succeeds.
2. Run jupyter labextension develop . --overwrite from the root of my local package repo.

Error occurs:

(base) jweill@f0189814e6a5 jlab-enhanced-cell-toolbar % jupyter labextension develop . --overwrite
Traceback (most recent call last):
  File "/Users/jweill/git/jlab-enhanced-cell-toolbar/setup.py", line 8, in <module>
    from jupyter_packaging import (
ModuleNotFoundError: No module named 'jupyter_packaging'
An error occurred.
FileNotFoundError: The Python package `.` is not a valid package, it is missing the `setup.py` file.
See the log file for details:  /var/folders/ll/xhm_lj355zng4kbnktyz3pdh0000gs/T/jupyterlab-debug-r1ig1e2x.log

(Will add the contents of the log in the first comment)

Expected behavior

Command completes without errors.

Context

macOS 11.6.2 (Big Sur) with conda 4.11.0 and Python 3.9.7.

[JasonWeill]

Full error log: jupyterlab-debug-r1ig1e2x.log

[fcollonval]

Hey @jweill-aws thanks for reporting. If you have the time to update this project to the latest extension cookiecutter, it should fix the error.

[fcollonval]

Closing as fixed by #44