`jupyter labextension watch --help` crashes with a KeyError #15540

akx · 2023-12-19T08:21:23Z

Description / Reproduce

~ $ docker run -it python:3.12 bash
# pip install jupyterlab
Successfully installed MarkupSafe-2.1.3 anyio-4.2.0 argon2-cffi-23.1.0 argon2-cffi-bindings-21.2.0 arrow-1.3.0 asttokens-2.4.1 async-lru-2.0.4 attrs-23.1.0 babel-2.14.0 beautifulsoup4-4.12.2 bleach-6.1.0 certifi-2023.11.17 cffi-1.16.0 charset-normalizer-3.3.2 comm-0.2.0 debugpy-1.8.0 decorator-5.1.1 defusedxml-0.7.1 executing-2.0.1 fastjsonschema-2.19.0 fqdn-1.5.1 idna-3.6 ipykernel-6.27.1 ipython-8.18.1 isoduration-20.11.0 jedi-0.19.1 jinja2-3.1.2 json5-0.9.14 jsonpointer-2.4 jsonschema-4.20.0 jsonschema-specifications-2023.11.2 jupyter-client-8.6.0 jupyter-core-5.5.1 jupyter-events-0.9.0 jupyter-lsp-2.2.1 jupyter-server-2.12.1 jupyter-server-terminals-0.5.0 jupyterlab-4.0.9 jupyterlab-pygments-0.3.0 jupyterlab-server-2.25.2 matplotlib-inline-0.1.6 mistune-3.0.2 nbclient-0.9.0 nbconvert-7.13.0 nbformat-5.9.2 nest-asyncio-1.5.8 notebook-shim-0.2.3 overrides-7.4.0 packaging-23.2 pandocfilters-1.5.0 parso-0.8.3 pexpect-4.9.0 platformdirs-4.1.0 prometheus-client-0.19.0 prompt-toolkit-3.0.43 psutil-5.9.7 ptyprocess-0.7.0 pure-eval-0.2.2 pycparser-2.21 pygments-2.17.2 python-dateutil-2.8.2 python-json-logger-2.0.7 pyyaml-6.0.1 pyzmq-25.1.2 referencing-0.32.0 requests-2.31.0 rfc3339-validator-0.1.4 rfc3986-validator-0.1.1 rpds-py-0.15.2 send2trash-1.8.2 six-1.16.0 sniffio-1.3.0 soupsieve-2.5 stack-data-0.6.3 terminado-0.18.0 tinycss2-1.2.1 tornado-6.4 traitlets-5.14.0 types-python-dateutil-2.8.19.14 uri-template-1.3.0 urllib3-2.1.0 wcwidth-0.2.12 webcolors-1.13 webencodings-0.5.1 websocket-client-1.7.0
# jupyter labextension watch --help .
Failed collecting help-message for alias 'development', due to: 'BuildLabExtensionApp'
Traceback (most recent call last):
  File "/usr/local/bin/jupyter-labextension", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/local/lib/python3.12/site-packages/jupyter_core/application.py", line 281, in launch_instance
    super().launch_instance(argv=argv, **kwargs)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 1076, in launch_instance
    app.initialize(argv)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 118, in inner
    return method(app, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/jupyter_core/application.py", line 252, in initialize
    self.parse_command_line(argv)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 118, in inner
    return method(app, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 858, in parse_command_line
    return self.initialize_subcommand(subc, subargv)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 118, in inner
    return method(app, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 722, in initialize_subcommand
    self.subapp.initialize(argv)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 118, in inner
    return method(app, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/jupyter_core/application.py", line 252, in initialize
    self.parse_command_line(argv)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 118, in inner
    return method(app, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 870, in parse_command_line
    self.print_help("--help-all" in interpreted_argv)
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 634, in print_help
    print("\n".join(self.emit_help(classes=classes)))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 643, in emit_help
    yield from self.emit_options_help()
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 596, in emit_options_help
    yield from self.emit_alias_help()
  File "/usr/local/lib/python3.12/site-packages/traitlets/config/application.py", line 534, in emit_alias_help
    cls = classdict[classname]
          ~~~~~~~~~^^^^^^^^^^^
KeyError: 'BuildLabExtensionApp'
#

Not much to diagnose: the command doesn't work.

Expected behavior

Help for labextension watch should work.

Context

Operating System and version: any, likely; reproducable on macOS and a Linux Docker container
JupyterLab version: 4.0.9

Troubleshoot Output

$PATH: /usr/local/bin /usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin

sys.path:
/usr/local/bin
/usr/local/lib/python312.zip
/usr/local/lib/python3.12
/usr/local/lib/python3.12/lib-dynload
/usr/local/lib/python3.12/site-packages

sys.executable:
/usr/local/bin/python

sys.version:
3.12.1 (main, Dec 9 2023, 00:02:46) [GCC 12.2.0]

platform.platform():
Linux-6.5.11-linuxkit-aarch64-with-glibc2.36

which -a jupyter:
/usr/local/bin/jupyter
/usr/local/bin/jupyter

pip list:
Package Version
------------------------- ----------
anyio 4.2.0
argon2-cffi 23.1.0
argon2-cffi-bindings 21.2.0
arrow 1.3.0
asttokens 2.4.1
async-lru 2.0.4
attrs 23.1.0
Babel 2.14.0
beautifulsoup4 4.12.2
bleach 6.1.0
certifi 2023.11.17
cffi 1.16.0
charset-normalizer 3.3.2
comm 0.2.0
debugpy 1.8.0
decorator 5.1.1
defusedxml 0.7.1
executing 2.0.1
fastjsonschema 2.19.0
fqdn 1.5.1
idna 3.6
ipykernel 6.27.1
ipython 8.18.1
isoduration 20.11.0
jedi 0.19.1
Jinja2 3.1.2
json5 0.9.14
jsonpointer 2.4
jsonschema 4.20.0
jsonschema-specifications 2023.11.2
jupyter_client 8.6.0
jupyter_core 5.5.1
jupyter-events 0.9.0
jupyter-lsp 2.2.1
jupyter_server 2.12.1
jupyter_server_terminals 0.5.0
jupyterlab 4.0.9
jupyterlab_pygments 0.3.0
jupyterlab_server 2.25.2
MarkupSafe 2.1.3
matplotlib-inline 0.1.6
mistune 3.0.2
nbclient 0.9.0
nbconvert 7.13.0
nbformat 5.9.2
nest-asyncio 1.5.8
notebook_shim 0.2.3
overrides 7.4.0
packaging 23.2
pandocfilters 1.5.0
parso 0.8.3
pexpect 4.9.0
pip 23.2.1
platformdirs 4.1.0
prometheus-client 0.19.0
prompt-toolkit 3.0.43
psutil 5.9.7
ptyprocess 0.7.0
pure-eval 0.2.2
pycparser 2.21
Pygments 2.17.2
python-dateutil 2.8.2
python-json-logger 2.0.7
PyYAML 6.0.1
pyzmq 25.1.2
referencing 0.32.0
requests 2.31.0
rfc3339-validator 0.1.4
rfc3986-validator 0.1.1
rpds-py 0.15.2
Send2Trash 1.8.2
setuptools 69.0.2
six 1.16.0
sniffio 1.3.0
soupsieve 2.5
stack-data 0.6.3
terminado 0.18.0
tinycss2 1.2.1
tornado 6.4
traitlets 5.14.0
types-python-dateutil 2.8.19.14
uri-template 1.3.0
urllib3 2.1.0
wcwidth 0.2.12
webcolors 1.13
webencodings 0.5.1
websocket-client 1.7.0
wheel 0.42.0

The text was updated successfully, but these errors were encountered:

welcome · 2023-12-19T08:21:27Z

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jtpio · 2023-12-19T09:12:04Z

Thanks @akx for the report!

It looks like the aliases defined here refer to BuildLabExtensionApp instead of WatchLabExtensionApp:

jupyterlab/jupyterlab/labextensions.py

Lines 310 to 314 in 8c5aa3a

    
           aliases = { 
        
               "development": "BuildLabExtensionApp.development", 
        
               "source-map": "BuildLabExtensionApp.source_map", 
        
               "core-path": "BuildLabExtensionApp.core_path", 
        
           }

Updating with the following code should help fix it:

aliases = {
    "development": "WatchLabExtensionApp.development",
    "source-map": "WatchLabExtensionApp.source_map",
    "core-path": "WatchLabExtensionApp.core_path",
}

Would you like to open a PR? Thanks!

akx · 2023-12-19T10:54:13Z

Would you like to open a PR? Thanks!

Sure thing! Took a while to get to that point because of lunch and #15541...

Fixes jupyterlab#15540

Fixes #15540

akx added the bug label Dec 19, 2023

jupyterlab-probot bot added the status:Needs Triage Applied to new issues that need triage label Dec 19, 2023

jtpio added the good first issue label Dec 19, 2023

jtpio added this to the 4.0.x milestone Dec 19, 2023

akx added a commit to akx/jupyterlab that referenced this issue Dec 19, 2023

Fix WatchLabExtensionApp.aliases so --help works

5932567

Fixes jupyterlab#15540

akx mentioned this issue Dec 19, 2023

Fix jupyter labextension watch --help #15542

Merged

jtpio closed this as completed in #15542 Dec 19, 2023

jtpio pushed a commit that referenced this issue Dec 19, 2023

Fix WatchLabExtensionApp.aliases so --help works (#15542)

cc800df

Fixes #15540

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`jupyter labextension watch --help` crashes with a KeyError #15540

`jupyter labextension watch --help` crashes with a KeyError #15540

akx commented Dec 19, 2023

welcome bot commented Dec 19, 2023

jtpio commented Dec 19, 2023

akx commented Dec 19, 2023

jupyter labextension watch --help crashes with a KeyError #15540

jupyter labextension watch --help crashes with a KeyError #15540

Comments

akx commented Dec 19, 2023

Description / Reproduce

Expected behavior

Context

welcome bot commented Dec 19, 2023

jtpio commented Dec 19, 2023

akx commented Dec 19, 2023

`jupyter labextension watch --help` crashes with a KeyError #15540

`jupyter labextension watch --help` crashes with a KeyError #15540