Abaels-MBP:notebook-myfork abaelhe$ pip install jupyterlab_powerpoint
Defaulting to user installation because normal site-packages is not writeable
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple, https://mirror.baidu.com/pypi/simple
Collecting jupyterlab_powerpoint
  Downloading https://pypi.tuna.tsinghua.edu.cn/packages/67/b3/7c65696326b35c2cf62f7203ddc6915518769b3281297762505496c02cbb/jupyterlab_powerpoint-0.1.0-py2.py3-none-any.whl (22 kB)
Collecting python-pptx>=0.6.0

……

Building wheels for collected packages: python-pptx
  Building wheel for python-pptx (setup.py) ... done
  Created wheel for python-pptx: filename=python_pptx-0.6.18-py3-none-any.whl size=275703 sha256=2cc60bf3fd5d8de7909a47cf2318248fe7f966f64da1014be413db2274abd19c
  Stored in directory: /Users/abaelhe/Library/Caches/pip/wheels/2c/92/3f/c614b86f8f18dc83f377a94e76a2f2fb1a1b6d5d74d438d2f4
Successfully built python-pptx
Installing collected packages: lxml, XlsxWriter, python-pptx, jupyterlab-powerpoint
Successfully installed XlsxWriter-1.3.3 jupyterlab-powerpoint-0.1.0 lxml-4.5.2 python-pptx-0.6.18
Abaels-MBP:notebook-myfork abaelhe$ jupyter labextension install jupyterlab_powerpoint
jupyter serverextension enable --py jupyterlab_powerpointjupyter serverextension enable --py jupyterlab_powerpointjupyter serverextension enable --py jupyterlab_powerpointBuilding jupyterlab assets (build:prod:minimize)
--- Logging error ---
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/shutil.py", line 670, in _rmtree_safe_fd
    os.unlink(entry.name, dir_fd=topfd)
PermissionError: [Errno 13] Permission denied: '403.html'

During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/logging/__init__.py", line 1081, in emit
    msg = self.format(record)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/logging/__init__.py", line 925, in format
    return fmt.format(record)
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/traitlets/config/application.py", line 117, in format
    return super(LevelFormatter, self).format(record)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/logging/__init__.py", line 672, in format
    record.exc_text = self.formatException(record.exc_info)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/logging/__init__.py", line 622, in formatException
    traceback.print_exception(ei[0], ei[1], tb, None, sio)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/traceback.py", line 103, in print_exception
    for line in TracebackException(
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/traceback.py", line 479, in __init__
    if (exc_value and exc_value.__cause__ is not None
AttributeError: 'str' object has no attribute '__cause__'
Call stack:
  File "/Users/abaelhe/Library/Python/3.8/bin/jupyter-labextension", line 8, in <module>
    sys.exit(main())
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyter_core/application.py", line 270, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/traitlets/config/application.py", line 664, in launch_instance
    app.start()
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/labextensions.py", line 308, in start
    super(LabExtensionApp, self).start()
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyter_core/application.py", line 259, in start
    self.subapp.start()
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/labextensions.py", line 104, in start
    build(clean_staging=self.should_clean,
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/commands.py", line 459, in build
    return handler.build(name=name, version=version, static_url=static_url,
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/commands.py", line 640, in build
    self._populate_staging(
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/commands.py", line 1100, in _populate_staging
    _rmtree(templates, self.logger)
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/commands.py", line 1824, in _rmtree
    shutil.rmtree(path, onerror=onerror)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/shutil.py", line 715, in rmtree
    _rmtree_safe_fd(fd, path, onerror)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/shutil.py", line 672, in _rmtree_safe_fd
    onerror(os.unlink, fullname, sys.exc_info())
  File "/Users/abaelhe/Library/Python/3.8/lib/python/site-packages/jupyterlab/commands.py", line 1822, in onerror
    logger.debug('Error in shutil.rmtree', exc_info=exc_info)
Message: 'Error in shutil.rmtree'
Arguments: ()
--- Logging error ---
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/shutil.py", line 670, in _rmtree_safe_fd
    os.unlink(entry.name, dir_fd=topfd)
PermissionError: [Errno 13] Permission denied: 'partial.html'

……

An error occured.

This looks like a problem with jupyter, possibly related to the permission error. Have you tried a jupyter forum for help?

"traceback.py" exception occurred During handling of the jupyter exception;
that denotes we need more robust "traceback.py";
i have submit PR:
https://github.com/python/cpython/pull/22064

I'm not convinced. Isn't the real problem that exc_value is a str, and you're just hiding that problem now?

jupyterlab bug